Home |
Search |
Today's Posts |
|
Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
Reply |
|
LinkBack | Thread Tools | Display Modes |
#1
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
I have a Dell E152FPc Flat screen Monitor 15" that goes black after
about a second after it is powered on. The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. I have never had one of these apart and am not really sure what I am in for. Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Would greatly appreciate any help. Thanks so much!!! S. |
#2
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Samantha wrote:
I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. I have never had one of these apart and am not really sure what I am in for. Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Most likely bad capacitors in the inverter (or the bulk supply feeding it). There are a HUGE number of Dell variants so you might be able to find a similar monitor with a different set of "trailing letters" in the model number (I've never bothered to sort out the presumed meaning of all these variations) Most of these cases snap together. A very small slotted screwdriver and/or one of the "blanks" used to fill an empty "card slot" in a PC is invaluable. Find a seam between the front and rear halves of the display's case. *Think* about how the two pieces are probably fitted together (i.e., one fits inside/behind the other). Then, slide your tool into the seam and *gently* pry them apart. You can usually slide the tool along the seam until you can "feel" where the catches are located. Usually, there is symmetry -- the catches on the left side are placed in the same locations as those along the right edge; ditto for top and bottom (within reason). Also, there tends to be symmetry about the vertical and horizontal axes -- so, if there is a catch 1" down (from the top) the left side, there is probably one 1" *up* (from the bottom) on that side. Experiment along the bottom -- someplace where your mistakes aren't as cosmetically visible. (remember, plastic deforms easily so you can easily gouge it with your tool). Good luck! |
#3
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
In article ,
D Yuniskis wrote: Samantha wrote: I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. I have never had one of these apart and am not really sure what I am in for. Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Most likely bad capacitors in the inverter (or the bulk supply feeding it). There are a HUGE number of Dell variants so you might be able to find a similar monitor with a different set of "trailing letters" in the model number (I've never bothered to sort out the presumed meaning of all these variations) Most of these cases snap together. A very small slotted screwdriver and/or one of the "blanks" used to fill an empty "card slot" in a PC is invaluable. Find a seam between the front and rear halves of the display's case. *Think* about how the two pieces are probably fitted together (i.e., one fits inside/behind the other). Then, slide your tool into the seam and *gently* pry them apart. You can usually slide the tool along the seam until you can "feel" where the catches are located. Usually, there is symmetry -- the catches on the left side are placed in the same locations as those along the right edge; ditto for top and bottom (within reason). Also, there tends to be symmetry about the vertical and horizontal axes -- so, if there is a catch 1" down (from the top) the left side, there is probably one 1" *up* (from the bottom) on that side. Experiment along the bottom -- someplace where your mistakes aren't as cosmetically visible. (remember, plastic deforms easily so you can easily gouge it with your tool). Good luck! Thanks, am fighting a really bad summer cold right now and am not really up to messing with it.. But in the next day or so I will probably feel well enough to take a crack at it... Appreciated everyones input! |
#4
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Tue, 06 Oct 2009 18:19:51 -0500, Samantha
wrote: I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. The LCD backlighting inverter has died. Everything else is probably just fine. The really tiny inverters are tricky to repair as a shorted turn on the xformer will usually blow up all the switching FET's. However, this one is big and easy to work on. I still suggest replacement. Tear apart the monitor and get the part number off the LCD inverter. Then search eBay and Google for a scrap replacement. One of these looks right: http://www.lcdrepair.us/e152-e153fpc-inverter-power.html $40. http://www.lcdrepair.us/e152-e153fpc-inverter-power-2.html $30 I have never had one of these apart and am not really sure what I am in for. Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Bulging and leaking electrolytic caps are the most common problem. Look at the board and you'll see about 8 electrolytic capacitors. If they're even slighly bulging, they're bad. I'm lazy and replace them all rather than trying to figure out which ones are blown. However, with LCD inverters, the switching FET's are also commonly fried. If replacing the caps doesn't work, I suggest just buying a replacement board.. Would greatly appreciate any help. Ummm.... you've heard of Google perhaps? http://video.google.com/videosearch?hl=en&source=hp&q=lcd+monitor+repair# http://www.lcd-monitor-repair.com Lots more when searching for "LCD monitor repair". -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
#5
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Wed, 07 Oct 2009 08:27:36 -0400, Meat Plow
wrote: Weakest link = inverters. Verify voltage source first, forget what they usually run but a guess would be around 20 vdc? Now I know why we used to kill off a tech a year in the 2-way biz in Smog Angeles during the 60's and 70's. They didn't know low from high voltage. Duz the big fat insulation on the output leads offer a clue? Try about 500-700VDC output. http://www.fonerbooks.com/test.htm The frequency range is also a problem. These bests run around 30-70Khz which is often beyond the upper frequency range of the typical DVG (Digital-Volts-Guesser). I'm not sure if the high frequency or the high voltage did the damage but I've killed at least 2 cheapo (Harbor Freight) DVM's measuring LCD inverter output. I've also managed to get electrocuted several times, mostly due to haste, sloppiness, clip leads, or all the aformentioned. -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
#6
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Wed, 07 Oct 2009 16:20:12 -0700, Jeff Liebermann
wrote: On Tue, 06 Oct 2009 18:19:51 -0500, Samantha wrote: I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. The LCD backlighting inverter has died. Everything else is probably just fine. The really tiny inverters are tricky to repair as a shorted turn on the xformer will usually blow up all the switching FET's. However, this one is big and easy to work on. I still suggest replacement. Tear apart the monitor and get the part number off the LCD inverter. Then search eBay and Google for a scrap replacement. One of these looks right: http://www.lcdrepair.us/e152-e153fpc-inverter-power.html $40. http://www.lcdrepair.us/e152-e153fpc-inverter-power-2.html $30 I have never had one of these apart and am not really sure what I am in for. Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Bulging and leaking electrolytic caps are the most common problem. Look at the board and you'll see about 8 electrolytic capacitors. If they're even slighly bulging, they're bad. I'm lazy and replace them all rather than trying to figure out which ones are blown. However, with LCD inverters, the switching FET's are also commonly fried. If replacing the caps doesn't work, I suggest just buying a replacement board.. Would greatly appreciate any help. Ummm.... you've heard of Google perhaps? http://video.google.com/videosearch?hl=en&source=hp&q=lcd+monitor+repair# http://www.lcd-monitor-repair.com Lots more when searching for "LCD monitor repair". Most of the monitor repair sites are nothiing more than an attempt to sell an overpriced book 'How to repair LCD monitors'. This specific problem is often referred to as the 'two seconds to black' failure. A quick explanation of the operation of most inverters, and the failu The inverter has a controller IC that generates the signals that drive the transformers AND monitors the voltage and current outputs of the inverter. Usually the start up sequence consists of driving the CCFL backlights at full brightness for several seconds, then beginning to monitor the output voltage across and current through each CCFL. If the output voltage is too high or too low, or if the current is too high, for any CCFL the controller will shut down. Possible causes of this problem include bad CCFLs, a shorted transformer, breakdown of insulation in the wiring, or bad components in the monitoring circuits. The Dell E152FPc and related models use an unusual design in the inverter driver; a bad transistor can also cause this problem. And yes, bad capacitors could also be responsible. This monitor also combines the inverter with the power supply. This makes replacement difficult unless you can obtain a non-working identical monitor inexpensively. Buying through eBay is usually impractical. The cost of shipping is prohibitive. Rather than spending the time and money to repair a 15" monitor in the USA I usually suggest watching the local Craigslist and Freecycle sites for somone giving away 'dead' LCD monitors. Currently I am using a 23" wide screen monitor I purchased for $15, and repaired by replacing ALL electrolytic caps at a cost of $7. My lates acquisition was a 19" Dell which had a broken power button. Not only was it a simple repair, the donor DELIVERED it!!! One site I STRONGLY recommend is www.badcaps.net/forum. They have extensive discussions on repairing many LCD monitors, including this one. Registration is required to post, but is free. PlainBill |
#7
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Jeff Liebermann wrote in
: On Wed, 07 Oct 2009 08:27:36 -0400, Meat Plow wrote: Weakest link = inverters. Verify voltage source first, forget what they usually run but a guess would be around 20 vdc? Now I know why we used to kill off a tech a year in the 2-way biz in Smog Angeles during the 60's and 70's. They didn't know low from high voltage. Duz the big fat insulation on the output leads offer a clue? Try about 500-700VDC output. I think he was talking about INPUT DC being ~20VDC http://www.fonerbooks.com/test.htm The frequency range is also a problem. These bests run around 30-70Khz which is often beyond the upper frequency range of the typical DVG (Digital-Volts-Guesser). I'm not sure if the high frequency or the high voltage did the damage but I've killed at least 2 cheapo (Harbor Freight) DVM's measuring LCD inverter output. Because they are only 1 Meg input Z. I took one apart to check it,was debating redoing the divider to 10MegR total.Also,the AC section will not handle freqs over 1 Khz. I've also managed to get electrocuted several times, mostly due to haste, sloppiness, clip leads, or all the aformentioned. Not "electrocuted",but shocked. "electrocution" is to KILL with electricity. Since you're still posting,you aren't killed. ;-) BTW,you can make a nifty HV probe for a 10Meg DMM by using a string of 22.5Meg 1% metal film R's to make 90 MegR,and putting it inside a plastic tube like an old tuning tool,solder to a 6-32 screw and threaded 1/4" hex spacer,a wire lead with banana plug on the other end,and use an old TEK 500 series probe hook-tip,or other TEK accessory tips. Makes a nice 10:1 probe,and 100 MegR doesn't load the HV supplies so much. I've used mine for a couple of decades. -- Jim Yanik jyanik at localnet dot com |
#8
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Oct 6, 6:19*pm, Samantha wrote:
I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. *The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. * I have never had one of these apart and am not really sure what I am in for. *Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Would greatly appreciate any help. Thanks so much!!! S. I recently repaired 3 E153FP's, which I believe are virtually identical. The problem was a 1000uF, 16 volt capacitor, used for the power supply. It had excessively high ESR, and I am assuming it caused excessively high ripple voltage which was making the LCD's control circuitry wack out (that's my very technical description of what I thought was going on, ha ha). I replaced the same cap on all 3 - It was easy to identify, about the largest cap on the board, the PCB material was darkened around it, and the top of the cap was bulged. Good luck! The 3 I fixed had the exact same symptom you describe, and have been back in service for about 3 months with no further problems. -Jake |
#9
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Oct 6, 6:19*pm, Samantha wrote:
I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. *The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. * I have never had one of these apart and am not really sure what I am in for. *Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Would greatly appreciate any help. Thanks so much!!! S. I recently repaired 3 E153FP's, which I believe are virtually identical. The problem was a 1000uF, 16 volt capacitor, used for the power supply. It had excessively high ESR, and I am assuming it caused excessively high ripple voltage which was making the LCD's control circuitry wack out (that's my very technical description of what I thought was going on, ha ha). I replaced the same cap on all 3 - It was easy to identify, about the largest cap on the board, the PCB material was darkened around it, and the top of the cap was bulged. Good luck! The 3 I fixed had the exact same symptom you describe, and have been back in service for about 3 months with no further problems. -Jake |
#10
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Oct 6, 6:19*pm, Samantha wrote:
I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. *The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. * I have never had one of these apart and am not really sure what I am in for. *Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Would greatly appreciate any help. Thanks so much!!! S. I recently repaired 3 E153FP's, which I believe are virtually identical. The problem was a 1000uF, 16 volt capacitor, used for the power supply. It had excessively high ESR, and I am assuming it caused excessively high ripple voltage which was making the LCD's control circuitry wack out (that's my very technical description of what I thought was going on, ha ha). I replaced the same cap on all 3 - It was easy to identify, about the largest cap on the board, the PCB material was darkened around it, and the top of the cap was bulged. Good luck! The 3 I fixed had the exact same symptom you describe, and have been back in service for about 3 months with no further problems. -Jake |
#11
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Jake wrote:
On Oct 6, 6:19 pm, Samantha wrote: I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. I have never had one of these apart and am not really sure what I am in for. Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Would greatly appreciate any help. Thanks so much!!! I recently repaired 3 E153FP's, which I believe are virtually identical. Dell has subtle variations in these monitors -- none that I have been able to *quickly* identify (at least not enough that I could open one and determine which model it was just by examining its contents!) The problem was a 1000uF, 16 volt capacitor, used for the power supply. It had excessively high ESR, and I am assuming it caused excessively high ripple voltage which was making the LCD's control circuitry wack out (that's my very technical description of what I thought was going on, ha ha). I replaced the same cap on all 3 - It was easy to identify, about the largest cap on the board, the PCB material was darkened around it, and the top of the cap was bulged. The PCB darkening is usually from the nearby switching transistor. When replacing the cap(s), select high temperature devices (105C) from "reputable" manufacturers (I like panasonic). You want a low ESR cap on most of these applications -- something "designed for switching applications" (I like the FM series as a reasonable cost/performance point). Note that you can also purchase different *grades* of "low ESR caps". So, if you are repairing a particularly "cherry" monitor for your *own* use, you might opt for something rated at ~10,000 hours (instead of ~5,000). Also, pay careful attention to the *height* of the component! I've been bitten by components that were just a bit too tall to fit back into the case (*with* the metalic shield installed). Lead spacing is also a concern but usually something you can work around. Good luck! The 3 I fixed had the exact same symptom you describe, and have been back in service for about 3 months with no further problems. It probably wouldn't hurt to examine the other caps on the board for "likely future failures". Certain manufacturers tend to have lots of early failures (I joke that "Xom" in the name means "gonna crap out soon"). Since most of the "cost" of the repair is getting the unit apart and then back together, the extra time and expense to replace all likely candidates seems justifiable. |
#12
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Thu, 08 Oct 2009 08:59:47 -0700, D Yuniskis
wrote: Jake wrote: On Oct 6, 6:19 pm, Samantha wrote: I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. I have never had one of these apart and am not really sure what I am in for. Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Would greatly appreciate any help. Thanks so much!!! I recently repaired 3 E153FP's, which I believe are virtually identical. Dell has subtle variations in these monitors -- none that I have been able to *quickly* identify (at least not enough that I could open one and determine which model it was just by examining its contents!) The problem was a 1000uF, 16 volt capacitor, used for the power supply. It had excessively high ESR, and I am assuming it caused excessively high ripple voltage which was making the LCD's control circuitry wack out (that's my very technical description of what I thought was going on, ha ha). I replaced the same cap on all 3 - It was easy to identify, about the largest cap on the board, the PCB material was darkened around it, and the top of the cap was bulged. The PCB darkening is usually from the nearby switching transistor. When replacing the cap(s), select high temperature devices (105C) from "reputable" manufacturers (I like panasonic). You want a low ESR cap on most of these applications -- something "designed for switching applications" (I like the FM series as a reasonable cost/performance point). Note that you can also purchase different *grades* of "low ESR caps". So, if you are repairing a particularly "cherry" monitor for your *own* use, you might opt for something rated at ~10,000 hours (instead of ~5,000). Also, pay careful attention to the *height* of the component! I've been bitten by components that were just a bit too tall to fit back into the case (*with* the metalic shield installed). Lead spacing is also a concern but usually something you can work around. Good luck! The 3 I fixed had the exact same symptom you describe, and have been back in service for about 3 months with no further problems. It probably wouldn't hurt to examine the other caps on the board for "likely future failures". Certain manufacturers tend to have lots of early failures (I joke that "Xom" in the name means "gonna crap out soon"). Since most of the "cost" of the repair is getting the unit apart and then back together, the extra time and expense to replace all likely candidates seems justifiable. As a rule of thumb, when a monitor has a defective cap, I will replace the lot of them. As you point out, it's not worth the risk of having to open the monitor up again. I prefer Panasonic FM or FC series for replacements. Purchasing from Digikey, I can redo an entire monitor for under $10, including shipping. (OK, I seldom replace the 100 µF 450 Volt cap). PlainBill |
#13
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
|
#14
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Just want to extend my thanks to all those that answered my post.
Didn't find much online when I went and searched for it. This is the first time I have had had one of these apart and didn't really know what to expect. It belongs to my aunt and I said I would take a quick look at it. The bad cap list was a good tip, really appreciate that, as well as the PDF on how to disassemble the monitor. Tomorrow is a pretty full day for me so I hope to be feeling up to pulling this apart by saturday. Thanks again. S. |
#15
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Thu, 08 Oct 2009 10:51:39 -0700, D Yuniskis
wrote: Understood. My point is that the price/repair point is quickly moving to make 19" as uneconomical to fix as the 17's have become. Yep. I just did a quick search using Google Shopping for "19" LCD monitor". Quite a few refurbished units for $70 to $100. New for about $120 to $150. Not very economical to repair at $75/hr. I have a Dell that rotates. But, in order to do so, the display has to be "up" high enough (so the rotating end doesn't wack into the tabletop). This places the display too high for me in my normal usage. Not mine. However, I made my own out of a swivel plate with detents as inspired by: http://www.instructables.com/id/rotate-or-pivot-lcd-monitor/ The lazy susan is a bit too crude for me. However, all my office and home monitors are 4:3, not 16:9. They rotate quite easily. 16:9 wide screen monitors might seem a bit high, but I've built two of these for customers and they loved it. One is a script writer and the other a technical editor, which might explain their interest in portrait mode displays. [N.B. I have been told by folks who wear bifocals that even *my* display height is too high for them to use comfortably; they end up having to tip their heads too far back to bring the screen into the correct portion of the eyeglass lens to focus] I'm 61 years ancient, wear bifocals, and don't have a problem. That's because I don't use the bifocals in front of the screen. I'm fortunate and can still use the cheap "reading" glasses without correction for computer use. For driving, I need bifocals. Plug: Cheap prescription glasses: http://www.zennioptical.com I do a lot of DTP and have found that I can get pretty good performance out of nearly any "large-ish" display. When working on prose, etc. I zoom the image to "fit width". This gives me lots of detail (when you've got 1600 dots to play with : ) and enough of the page vertically that I can see what I am doing. I only look at full page views when I want to get a feel for the layout of the page, the location of whitespace, etc. Well, I've been told that I have no writing ability, no aesthetic sense, no appreciation of layout styles, and no artistic abilities. That's a sufficient to avoid DTP and other forms of real work. About the only layout work I do is some HTML, which is admittedly fairly badly done. Despite these limitations, I can usually adapt to any screen size or layout ranging from tiny Netbook and PDA displays, to projection screens. Getting a full page view doesn't do much for me. However, waiting a few days and taking a second look usually causes me to ask "what was I thinking"? More seriously, I cheat a bit and have two monitors and two computers on my desk at home. I have a switch that allows me to put both monitors on a dual display video card on the main machine. That's very useful if I want a huge workspace. I don't used it often, but when doing antenna design and 3D modeling, it's quite handy. A second monitor is invaluable in just about any desktop (not just DTP) application. It lets you work in one *full* screen while having another (full!) screen for other uses (e.g., floating pallets for image editing, "text" that you are copy/pasting into the actual application, a OCB schematic alongside the PCB *layout* you are working on, etc.) Yep. (there are currently six 21 inch LCDs awaiting pats in various states of disassembly... this causes a fair amount of grief! And, isn't realistic when you have pets : ) You haven't seen my office. 700 sq ft, mostly storage and bakers racks. http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html (scroll horizontally). I wouldn't have room for 6 monitors. In my case, the danger is not pets. It's visitors. Despite warnings, visitor always manage to smash into something. No fatalities, so far. If I did this for a *living*, I would just keep a spare inverter around and hack it into the "bad" display long enough to illuminate the display (using a nice "white" test screen) to check for these "smudges" before investing much time in the repair. I do that, but only for testing CCFL tubes. I always seem to forget to test the assembled panels. Thanks for the reminder. That's the problem. For example, I just bought a DC controller for an HP LaserJet 4200. Big crack on the formatter PCB. I could send it back as defective and get another, or just patch the board and be done with it. I'll probably phone the eBay vendor and see what he has to offer. That's one of the risks of buying obviously used parts. Exactly. And, if the cost of return postage becomes an issue, it might not be economical to even *try* to return it (most ebay sellers don't consider the threat of a "negative" to be important; especially if they are selling in volume) Nope. They just threaten to give me a negative review for daring to suggest they're selling crap and don't honor their alleged warranties. However, that's only happened once in perhaps 8 years, so I'm not worried about retaliation. In this case, I called the vendor, who indicated that I should try the board despite the crack, and see what happens. If it fails, he'll still honor the warranty. So, I crammed it into the HP LJ4200 (about 20 connectors) and it worked just fine. I slopped some epoxy on the crack and will deliver it tomorrow. No need to return it. Only to discover that the inverter's design had been changed mechanically. Not only had the connectors to the CCFL's been "rendered incompatible", but the board mounting wasn't compatible, either! Yep. Been there and had it happen. It's really ugly inside laptop LCD displays, where there's little room to maneuver. I just bought a replacement inverter for a Dell B130 laptop that had exactly the same part number as the original, but where the mounting hole was moved about 0.050". I took apart the mounting bracket, filed the hole to fit and reassembled. 20 minutes totally wasted. Other laptops were not so easy. I've had to use hot melt glue to secure some inverters. frown Would have been better (from a standpoint of my time) had they *both* been defective! ;-) On the other foot, I have nothing against cannibalism. On motherboards, replacing caps is considerably more risky as the boards are often 4 (or even 6) layers and often don't have thermal reliefs around the caps. Unless it is a particularly nice board, I don't bother (you also have no way of knowing if the high ripple on those power signals hasn't toasted something else in the design. Yep. I have a Pace desoldering station with a motorized vacuum pump. It's strong enough to suck the pad off the board if necessary. Some boards offer some relief around the leads, while others are so tight as to defy removal. I have a method to deal with caps that's somewhat non-conventional. I have a cable cutter, with semi-circular cutters, that I use to chop off the top of the cap near the base. I then remove what's left of the base, leaving only two leads projecting from the PCB. I grab a lead with pliers, heat the joint, and pull them out, one at a time. Works nicely and much better than the Pace desoldering station. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#16
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Jeff Liebermann wrote:
On Thu, 08 Oct 2009 10:51:39 -0700, D Yuniskis Understood. My point is that the price/repair point is quickly moving to make 19" as uneconomical to fix as the 17's have become. Yep. I just did a quick search using Google Shopping for "19" LCD monitor". Quite a few refurbished units for $70 to $100. New for about $120 to $150. Not very economical to repair at $75/hr. And their prices continue to fall. So, you fix one only to find it "competing" with a new, *warrantied* unit for roughly the same price. I have a Dell that rotates. But, in order to do so, the display has to be "up" high enough (so the rotating end doesn't wack into the tabletop). This places the display too high for me in my normal usage. Not mine. However, I made my own out of a swivel plate with detents as inspired by: http://www.instructables.com/id/rotate-or-pivot-lcd-monitor/ The lazy susan is a bit too crude for me. However, all my office and home monitors are 4:3, not 16:9. They rotate quite easily. 16:9 wide screen monitors might seem a bit high, but I've built two of these for customers and they loved it. One is a script writer and the other a technical editor, which might explain their interest in portrait mode displays. I'd rather wider. I tried a three monitor setup once and *loved* it. But, my current machine doesn't like having lots of video cards :-( [N.B. I have been told by folks who wear bifocals that even *my* display height is too high for them to use comfortably; they end up having to tip their heads too far back to bring the screen into the correct portion of the eyeglass lens to focus] I'm 61 years ancient, wear bifocals, and don't have a problem. That's because I don't use the bifocals in front of the screen. I'm fortunate and can still use the cheap "reading" glasses without correction for computer use. For driving, I need bifocals. Yes, I think the problem is with folks whose reading and computer Rx's are different. E.g., I know people with "computer bifocals" (the near Rx is set for the distance to the screen while the far is set for "distance") and "regular bifocals" (near Rx is set for reading with far set for "distance"). Apparently, trying to read "close up" through the "computer Rx" is where the problem lies (I once saw a pair of lenses cut with *four* different regions in each lens -- I guess predating "progressive" lenses?) Thankfully, I still only need glasses for distance -- though reading the markings on some components either requires bright light *or* a magnifying glass (e.g. reading glasses) Apparently a consequence of losing "focusing power" with age. Plug: Cheap prescription glasses: http://www.zennioptical.com I do a lot of DTP and have found that I can get pretty good performance out of nearly any "large-ish" display. When working on prose, etc. I zoom the image to "fit width". This gives me lots of detail (when you've got 1600 dots to play with : ) and enough of the page vertically that I can see what I am doing. I only look at full page views when I want to get a feel for the layout of the page, the location of whitespace, etc. Well, I've been told that I have no writing ability, no aesthetic sense, no appreciation of layout styles, and no artistic abilities. Ha! Sounds like a career in POLITICS should be right up your alley! ;-) I deliberately started taking on these kinds of work just to try to develop those skills. Spelling is sometimes a challenge (esp when it comes to "doubling the final consonant") but there are tools to help with that :-/ That's a sufficient to avoid DTP and other forms of real work. About the only layout work I do is some HTML, which is admittedly fairly badly done. Despite these limitations, I can usually adapt to any screen size or layout ranging from tiny Netbook and PDA displays, to projection screens. Getting a full page view doesn't do much for me. However, waiting a few days and taking a second look usually causes me to ask "what was I thinking"? More seriously, I cheat a bit and have two monitors and two computers on my desk at home. I have a switch that allows me to put both monitors on a dual display video card on the main machine. That's very useful if I want a huge workspace. I don't used it often, but when doing antenna design and 3D modeling, it's quite handy. I have my two primary machines attached to a pair of monitors with built-in A/B switches. So, I can have both monitors attached to either machine or one monitor on each. I keep the keyboard for one machine on the work surface and the other in a "keyboard drawer" beneath. I find this easier than using a KVM though, at times, I have a hard time remembering which keyboard to type on! :-/ (there are currently six 21 inch LCDs awaiting pats in various states of disassembly... this causes a fair amount of grief! And, isn't realistic when you have pets : ) You haven't seen my office. 700 sq ft, mostly storage and bakers racks. http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html jealous ;-) I work out of a spare bedroom for "head stuff" and commandeer appropriate floor space as needed (and usually incur much wrath in doing so!). I think it helps me keep things from getting out of control and ending up living in a "cave". (scroll horizontally). I wouldn't have room for 6 monitors. In my case, the danger is not pets. It's visitors. Despite warnings, visitor always manage to smash into something. No fatalities, so far. Visitors you can at least vent your anger on (even if you do it privately after they depart). With pets, you really can't blame them for their actions -- the fault lies squarely with *you*! frown If I did this for a *living*, I would just keep a spare inverter around and hack it into the "bad" display long enough to illuminate the display (using a nice "white" test screen) to check for these "smudges" before investing much time in the repair. I do that, but only for testing CCFL tubes. I always seem to forget to test the assembled panels. Thanks for the reminder. Well, *I* haven't learned that lesson, yet! : But, again, if I was doing this "for real", I would set things up more efficiently (I repair them for a local charity so I can't really invest much time/space in this) Only to discover that the inverter's design had been changed mechanically. Not only had the connectors to the CCFL's been "rendered incompatible", but the board mounting wasn't compatible, either! Yep. Been there and had it happen. It's really ugly inside laptop LCD displays, where there's little room to maneuver. I just bought a replacement inverter for a Dell B130 laptop that had exactly the same part number as the original, but where the mounting hole was moved about 0.050". I took apart the mounting bracket, filed the hole to fit and reassembled. 20 minutes totally wasted. Other laptops were not so easy. I've had to use hot melt glue to secure some inverters. Ouch. Owing to my time limitations, I am pretty reluctant about investing much "special effort" in fixes that aren't relatively straightforward. If I was *paid* for my time, I might think otherwise. Or, if the repair was for my own personal use. Otherwise, if I can't make it work without re-engineering the fix, it goes in the recycle pile... frown Would have been better (from a standpoint of my time) had they *both* been defective! ;-) On the other foot, I have nothing against cannibalism. Of course! I was originally *thrilled* with the idea that I could make a quick fix just by stealing parts from one for the other. A real "no-brainer". Hence the disappointment when I saw the *arbitrary* changes they had made in manufacturing... : On motherboards, replacing caps is considerably more risky as the boards are often 4 (or even 6) layers and often don't have thermal reliefs around the caps. Unless it is a particularly nice board, I don't bother (you also have no way of knowing if the high ripple on those power signals hasn't toasted something else in the design. Yep. I have a Pace desoldering station with a motorized vacuum pump. It's strong enough to suck the pad off the board if necessary. Some boards offer some relief around the leads, while others are so tight as to defy removal. Exactly. I have actually deliberately laid out some boards like this to discourage "amateur" repairs. Really obvious when someone lifts a pad because they weren't prepared to deal with a board laid out with such fine-line rules... I have a method to deal with caps that's somewhat non-conventional. I have a cable cutter, with semi-circular cutters, that I use to chop off the top of the cap near the base. I then remove what's left of the base, leaving only two leads projecting from the PCB. I grab a lead with pliers, heat the joint, and pull them out, one at a time. Works nicely and much better than the Pace desoldering station. I usually find that the thermal mass of the tip I am using (at the time) is just not enough to overcome any big ground planes, etc. And, rather than wait for the tip to cool so I can swap in something larger, I just move on to the next candidate. : Always more broken stuff waiting to be fixed than there is time available to fix it! (and it sure looks like the current "lack of quality" will be with us for quite a while!) |
#17
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Thu, 08 Oct 2009 18:06:27 -0700 Jeff Liebermann
wrote in Message id: : http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html Those scopes look ancient! |
#18
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Fri, 09 Oct 2009 05:09:29 -0400, JW wrote:
On Thu, 08 Oct 2009 18:06:27 -0700 Jeff Liebermann wrote in Message id: : http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html Those scopes look ancient! They work. There's another pile of scopes at home including some that are waiting for me to find time to repair: http://802.11junk.com/jeffl/pics/home/slides/BL-shop5.html Hmmm... that's an old photo that only shows about 1/3 of the pile. I guess my test equipment collection qualifies as a 1970's technology museum, but it's quite adequate for what I need. I'm currently considering a USB oscilloscope, so some of the old scopes may eventually be retired. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#19
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Thu, 08 Oct 2009 21:45:11 -0700, D Yuniskis
wrote: I'd rather wider. I tried a three monitor setup once and *loved* it. But, my current machine doesn't like having lots of video cards :-( I bought several ATI 2 port PCIe video cards. The county uses Matrox video cards in their emergency dispatch center to run up to 4 monitors. However, why stop at 3 monitors: http://www.wideview.it/wideview.htm http://www.wideview.it/pictures.htm Yes, I think the problem is with folks whose reading and computer Rx's are different. E.g., I know people with "computer bifocals" I can see that if they're transcribbling from notes or have to look at their fingers when typing. Seeing the screen is not a problem because it's fixed distance. However, the keyboard and copy might be anywhere between about 12" to 36". That's a good application for progressive lenses. Learning to type better and purchasing a copy stand might be alternatives. Fortunately, I can type at about 30 mistakes per minute without looking at the keyboard, so single vision is adequate for me. Thankfully, I still only need glasses for distance -- though reading the markings on some components either requires bright light *or* a magnifying glass (e.g. reading glasses) Apparently a consequence of losing "focusing power" with age. Yep. Same problem. I have a Maglite for exactly that purpose. The depth of field for my eyes increases when the pupil narrows under bright lights. Plug: Cheap prescription glasses: http://www.zennioptical.com Well, I've been told that I have no writing ability, no aesthetic sense, no appreciation of layout styles, and no artistic abilities. Ha! Sounds like a career in POLITICS should be right up your alley! Nope. I tried to get elected to the local water board and failed. I also have some bad habits and strange appearance that apparently affects my abilities to get elected: http://802.11junk.com/jeffl/pics/jeffl/slides/jeffl-wolf.html (Give it a few seconds to load). I also tend to go in circles: http://www.LearnByDestroying.com/panorama/jeffl.htm (Give it time to load. Then move the mouse around the photo). You haven't seen my office. 700 sq ft, mostly storage and bakers racks. http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html jealous ;-) That was when it was clean. I'll post a current photo when I get to the office in a few daze. Incidentally, I've been at the same location since about 1990, which might explain the accumulation of junk. Of course! I was originally *thrilled* with the idea that I could make a quick fix just by stealing parts from one for the other. A real "no-brainer". Hence the disappointment when I saw the *arbitrary* changes they had made in manufacturing... : That's not unusual. If you look carefully, the two parts were probably made by different vendors (both probably working from the same drawings but making different mistakes). Manufacturers like to have a single model number maintained as long as possible, even though the guts change radically. That's so they don't have a deluge of credit returns and restocking from their own dealers every time a new and improved model appears. That's very common in the wireless router business. For example, the Netgear WGR614 and Linksys WRT54G have 9 and 8 different hardware mutations respectively. Unless you know the trick, it's almost impossible to tell which version without ripping open the box. LCD monitors are not that bad, but close. Subtle variations in model numbers (usual a suffix) indicate radical variations in vendor and internals. Exactly. I have actually deliberately laid out some boards like this to discourage "amateur" repairs. Really obvious when someone lifts a pad because they weren't prepared to deal with a board laid out with such fine-line rules... Never attribute to malice that which is adequately explained by incompetence. I have a method to deal with caps that's somewhat non-conventional. I have a cable cutter, with semi-circular cutters, that I use to chop off the top of the cap near the base. I then remove what's left of the base, leaving only two leads projecting from the PCB. I grab a lead with pliers, heat the joint, and pull them out, one at a time. Works nicely and much better than the Pace desoldering station. Next opportunity, try it my way. Being able to eliminate the cazapitor as a heat sink, and having access to both sides of the lead, is a big plus. Even the big ground plane sinking doesn't seem to be as bad with the mass of the cazapitor gone. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#20
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
JW wrote:
On Thu, 08 Oct 2009 18:06:27 -0700 Jeff Liebermann wrote in Message id: : http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html Those scopes look ancient! Good scopes never die! : I still long for a Tek 454 (which probably also qualifies as ancient but is more than adequate for my nominal "analog" needs!). And, I groan when I think about how many tek probes I gave away over the years : (most of my work is digital so I am far more interested in the "micro hooks/grabbers) |
#21
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Jeff Liebermann wrote:
On Thu, 08 Oct 2009 21:45:11 -0700, D Yuniskis I'd rather wider. I tried a three monitor setup once and *loved* it. But, my current machine doesn't like having lots of video cards :-( I bought several ATI 2 port PCIe video cards. The county uses Matrox The machines that I am currently using are strictly PCI (i.e., not PCIe, x, AGP, etc.) so I have limited choices for video cards. And, most of the slots are already full: - USB2 - Wide SCSI - Wide Differential SCSI - Narrow SCSI - "sound" - Firewire so adding a video card (even a dual-headed card) means losing something else : video cards in their emergency dispatch center to run up to 4 monitors. However, why stop at 3 monitors: http://www.wideview.it/wideview.htm http://www.wideview.it/pictures.htm Yes, I think the problem is with folks whose reading and computer Rx's are different. E.g., I know people with "computer bifocals" I can see that if they're transcribbling from notes or have to look at Exactly. If you have written material that you need to consult, you're screwed. I'm lucky because my interactions are usually "original works" (so the "source" is in my head someplace) *or* I can have the "other documents" (e.g., datasheets) open on another monitor to consult -- instead of having to refer to paper. their fingers when typing. Seeing the screen is not a problem because it's fixed distance. However, the keyboard and copy might be anywhere between about 12" to 36". That's a good application for progressive lenses. Learning to type better and purchasing a copy stand might be alternatives. Fortunately, I can type at about 30 mistakes per minute without looking at the keyboard, so single vision is adequate for me. Thankfully, I still only need glasses for distance -- though reading the markings on some components either requires bright light *or* a magnifying glass (e.g. reading glasses) Apparently a consequence of losing "focusing power" with age. Yep. Same problem. I have a Maglite for exactly that purpose. The depth of field for my eyes increases when the pupil narrows under bright lights. Ah, I never thought of it in those terms! I have a pair of reading glasses with small LED lamps attached to each temple. I use them in lieu of a magnifying glass (much more convenient -- unless you only need to look at something *once*). If I am in a darkened area (like trying to read the connector designations on the back of a PC *under* my work table), then I flip on the LEDs for more illumination. To work on boards, I have a 70X (?) B&L stereomicroscope. Plug: Cheap prescription glasses: http://www.zennioptical.com Well, I've been told that I have no writing ability, no aesthetic sense, no appreciation of layout styles, and no artistic abilities. Ha! Sounds like a career in POLITICS should be right up your alley! Nope. I tried to get elected to the local water board and failed. I also have some bad habits and strange appearance that apparently affects my abilities to get elected: http://802.11junk.com/jeffl/pics/jeffl/slides/jeffl-wolf.html (Give it a few seconds to load). My browser isn't configured for animations (since those are usually "ads" -- why waste CPU cycles on something I don't care to see? : ) I also tend to go in circles: http://www.LearnByDestroying.com/panorama/jeffl.htm (Give it time to load. Then move the mouse around the photo). You haven't seen my office. 700 sq ft, mostly storage and bakers racks. http://802.11junk.com/jeffl/pics/office/slides/office-panorama-2.html jealous ;-) That was when it was clean. I'll post a current photo when I get to the office in a few daze. Incidentally, I've been at the same location since about 1990, which might explain the accumulation of junk. I have found that the adage of junk accumulating to fill available space is true. So, I severely restrict the "available space"! (clever, eh? : ) Living in the DSW means you can't store anything in anyplace *other* than "living area". So, that means only "inert" things (cables, mechanical parts, etc.) can be stored in the garage; everything else has to fit in the office or under a bed or in a closet. This makes space a premium. I think there are 10 or 11 computers running here (different operating systems, purposes, etc.) along with 7 or 8 printers (different capabilities ranging from "postcard printers" to "wide format"), three plotters (various sizes), three different scanners (up to B size) -- plus various other special purpose peripherals. You learn to get the most out of everything you have lest you find yourself needing something *else*! : Of course! I was originally *thrilled* with the idea that I could make a quick fix just by stealing parts from one for the other. A real "no-brainer". Hence the disappointment when I saw the *arbitrary* changes they had made in manufacturing... : That's not unusual. If you look carefully, the two parts were probably made by different vendors (both probably working from the same drawings but making different mistakes). Manufacturers like to Dunno. The two monitors in question have already been recycled. have a single model number maintained as long as possible, even though the guts change radically. That's so they don't have a deluge of credit returns and restocking from their own dealers every time a new and improved model appears. That's very common in the wireless router business. For example, the Netgear WGR614 and Linksys WRT54G have 9 and 8 different hardware mutations respectively. Unless you know the trick, it's almost impossible to tell which version without ripping open the box. LCD monitors are not that bad, but close. Subtle variations in model numbers (usual a suffix) indicate radical variations in vendor and internals. That seems to be particularly true of the Dell monitors (which is where this thread started) I have a method to deal with caps that's somewhat non-conventional. I have a cable cutter, with semi-circular cutters, that I use to chop off the top of the cap near the base. I then remove what's left of the base, leaving only two leads projecting from the PCB. I grab a lead with pliers, heat the joint, and pull them out, one at a time. Works nicely and much better than the Pace desoldering station. Next opportunity, try it my way. Being able to eliminate the cazapitor as a heat sink, and having access to both sides of the lead, is a big plus. Even the big ground plane sinking doesn't seem to be as bad with the mass of the cazapitor gone. I'll *try* to keep it in mind -- but expect to forget it! : (I've been changing the oil in my vehicles for decades and I always remember to put on the nitrile gloves *after* I am finished :-( |
#22
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Jeff Liebermann wrote:
alternatives. Fortunately, I can type at about 30 mistakes per minute without looking at the keyboard, so single vision is adequate for me. LOL! We must have had the same typing tutors! |
#23
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Jim Yanik wrote:
Jeff Liebermann I've also managed to get electrocuted several times, mostly due to haste, sloppiness, clip leads, or all the aformentioned. Not "electrocuted",but shocked. "electrocution" is to KILL with electricity. Since you're still posting,you aren't killed. ;-) Unless he is one of the new fast walking zombies (thanks Two and a Half Men). Michael |
#24
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
On Thu, 08 Oct 2009 13:00:17 -0700, D Yuniskis
wrote: wrote: As a rule of thumb, when a monitor has a defective cap, I will replace the lot of them. As you point out, it's not worth the risk of having to open the monitor up again. I prefer Panasonic FM or FC series for replacements. Purchasing from Digikey, I can redo an entire monitor for under $10, including shipping. (OK, I seldom replace the 100 µF 450 Volt cap). I've only seen one of these "bad" (in about 100 monitors). Despite the fact that they are often manufacture by the same company who manufactures the other (crappy) caps on the board! I guess the ripple currents are not as large (?) The large (rectified mains filter) is handling 120 Hz ripple (and the pulses from the SMPS). The filter caps on the secondary are handling 100 KHz or greater ripple. As I understand the problem, the ripple current will cause heating (duh!), which will cause the ESR to rise, causing more heating, until eventually a poorly made cap will vent. The mains filter cap has several advantages - much lower current and much more surface area to dissipate the heat. PlainBill |
#25
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Took the time today to open that monitor. It went pretty smoothly,
found all the tabs with the help of a small spackle knife. Found the buldging 1000uf 16v capacitor. Found a replacement on an old board from a TV and swapped the two. I have the monitor on and the test pattern up now. Have let it set for about an hour now. Will leave it for a few more to make sure nothing else happens... Want to give you all a lot of thanks for the help. I probably would have stumbled around inside there for quite awhile before I really figured out how it work. Knowing how something breaks (common failures) is invaluable when trying to troubleshoot something. Thanks to all!! S. |
#26
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
In article
, Jake wrote: On Oct 6, 6:19*pm, Samantha wrote: I have a Dell E152FPc Flat screen Monitor 15" that goes black after about a second after it is powered on. *The Green power light stays on and the color bar test pattern is there if you stick a flash light up to it. * I have never had one of these apart and am not really sure what I am in for. *Just looking at it, I don't see any obvious way to take it apart. There are some screws to take off the stand, but after that I am not sure. Anybody ever take one of these apart and fix it? Would greatly appreciate any help. Thanks so much!!! S. I recently repaired 3 E153FP's, which I believe are virtually identical. The problem was a 1000uF, 16 volt capacitor, used for the power supply. It had excessively high ESR, and I am assuming it caused excessively high ripple voltage which was making the LCD's control circuitry wack out (that's my very technical description of what I thought was going on, ha ha). I replaced the same cap on all 3 - It was easy to identify, about the largest cap on the board, the PCB material was darkened around it, and the top of the cap was bulged. Good luck! The 3 I fixed had the exact same symptom you describe, and have been back in service for about 3 months with no further problems. -Jake That is the same same with this one. Found a suitable replacement and done. Thanks!! |
#27
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Samantha wrote:
Took the time today to open that monitor. It went pretty smoothly, found all the tabs with the help of a small spackle knife. Found the buldging 1000uf 16v capacitor. Found a replacement on an old board from a TV and swapped the two. I have the monitor on and the test pattern up now. Have let it set for about an hour now. Will leave it for a few more to make sure nothing else happens... Want to give you all a lot of thanks for the help. I probably would have stumbled around inside there for quite awhile before I really figured out how it work. Knowing how something breaks (common failures) is invaluable when trying to troubleshoot something. Thanks to all!! S. Maybe you might already be aware of this ? but I'll spit it out in case some one else here may benefit from it. When ever replacing caps found bad like that, in inverter supplies, it's a good idea to make sure you use computer grade or some sort of low ESR types. This is one of the problems that plague these types of circuits and high ESR just pushing it along faster making the cap run warm. |
#28
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
|
#29
Posted to sci.electronics.repair
|
|||
|
|||
DeLL E152FPc Goes black after a second.
Samantha wrote:
Took the time today to open that monitor. It went pretty smoothly, found all the tabs with the help of a small spackle knife. Found the buldging 1000uf 16v capacitor. Found a replacement on an old board from a TV and swapped the two. I have the monitor on and the test pattern up now. Have let it set for about an hour now. Will leave it for a few more to make sure nothing else happens... Chances are (?), the "replacement cap" was not a high temperature device (though it might be... depends on where you cound it in the TV). You really want 105degree (C) devices as they tend to be higher reliability in these applications. Otherwise, you'll be replacing *it* soon! Also, check the manufacturer on the (bad) cap. Chances are there are a few other caps made by the same manufacturer on that board. Often best to just replace them all (I realize you are unlikely to find replacements for all of them on that "TV board" -- but, if you have to order a hi-temp cap you might as well order the rest of them if you want to keep the display running for any length of time) Omit the 400V cap as it seldom fails. Panasonic FM series caps seem to be a good tradeoff between cost and reliability. DOUBLE CHECK COMPONENT HEIGHTS/WIDTHS so you don't end up ordering things that won't fit! Want to give you all a lot of thanks for the help. I probably would have stumbled around inside there for quite awhile before I really figured out how it work. Knowing how something breaks (common failures) is invaluable when trying to troubleshoot something. Exactly. I use repair experiences to guide me in determining what to avoid when *designing* stuff. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Recycling Dell Laptop Batteries(dell laptop parts) | UK diy | |||
Dell DJ Dell pocket DJ battery replacement | Electronics Repair | |||
DELL support person ? anyone who can help reference a DELL LCD? | Electronics Repair | |||
Black display on Dell Inspiron 8000 | Electronics Repair | |||
Damaged Dell Flat Panel 2001FP, Dell says they don't repair flatpanels | Electronics Repair |