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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. |
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#1
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Fluke 8060a meter interconnect strip
I have an old IBM labelled Fluke built DMM (8060a equivalent) that hasn't worked in years for reasons I don't recall exactly, but seem to think it was stone dead. I had it apart and left in a box and, since my last 87 crapped out a few weeks ago, I needed the low ohms feature of one or the other so I took another look at the old IBM.
I found just about every electrolytic on the board physically leaky, and most down in value and ESR, some considerably. I replaced them all but when assembling the meter, I checked the two flexible rubber interconnect strips.. One of them is round and reads zero ohms all across it's length, so that one's good. The other is a flat rectangular piece, and I cannot get any kind of resistance reading *anywhere* across it. I've cleaned it several times including using an abrasive last time and cannot get a whiff of conductance, and I've put considerable pressure on the test leads. I guess it being unassembled and sitting in free air must have poisoned it somehow as I don't recall it having any issues with erratic segments before the meter died. It will be easy to hard wire this but was wondering if this is a low ohm transfer strip of something maybe a few ohms to a few thousand. If it's low ohms, I'll just hard wire it. If it's something other, there's plenty of room to put in 1/8 w resistors of appropriate value. Anyone know the approximate resistance of the strip? |
#3
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Fluke 8060a meter interconnect strip
On Sunday, May 1, 2016 at 3:41:23 PM UTC-4, wrote:
Anyone know the approximate resistance of the strip? It would not be in the best interest of any (legitimate) manufacturer to build a precision-resistance into an interconnect strip. As you have discovered, they can be volatile, and any actual planned resistance will necessarily generate heat - leading to even quicker failure. Hardwire it - and if it works properly (and it should if this is the only problem), you are done. Peter Wieck Melrose Park, PA |
#4
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Fluke 8060a meter interconnect strip
On Sunday, May 1, 2016 at 4:17:44 PM UTC-4, wrote:
On Sunday, May 1, 2016 at 3:41:23 PM UTC-4, wrote: Anyone know the approximate resistance of the strip? It would not be in the best interest of any (legitimate) manufacturer to build a precision-resistance into an interconnect strip. As you have discovered, they can be volatile, and any actual planned resistance will necessarily generate heat - leading to even quicker failure. Hardwire it - and if it works properly (and it should if this is the only problem), you are done. Peter Wieck Melrose Park, PA Thanks Peter. I don't think any resistance (assuming there is any) would be a problem. The strip in question feeds the LCD display glass and the draw would likely be few micro amps at 5V. I was thinking in terms of the conductive pads used to active scan lines in cheap keyboards. Those measure from a few dozen ohms to a few K ohms and work properly. In any case, I'll take your advice and hard wire it when I get to work tomorrow and see what happens. John |
#5
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Fluke 8060a meter interconnect strip
On Sun, 1 May 2016 12:41:20 -0700 (PDT), wrote:
Anyone know the approximate resistance of the strip? Some photos of the insides of an 8024a, which is fairly close in construction to an 8060a. http://www.eevblog.com/forum/testgear/fluke-8024b-33-years-old-and-still-going-strong!-beware-3mb-photos/ The ribbon cable: http://s193.photobucket.com/user/Bl4ckW0lfi3/media/Fluke8024B-09_zps4b433951.jpg.html The ribbon cable between the two boards is made from screened graphite, which tends to crack if flexed. I found a similar ribbon cable, but made from flattened copper wire that looked more reliable. I removed the original ribbon cable, clamped in the new cable, and after a bit of jiggling, got it to make a connection without soldering. Once it was working, I used hot melt glue to hold it in place. I suppose soldering would have been easier, but at the time, I didn't want to wreck the meter. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#6
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Fluke 8060a meter interconnect strip *update working-- sorta*
On Sunday, May 1, 2016 at 5:53:42 PM UTC-4, Jeff Liebermann wrote:
On Sun, 1 May 2016 12:41:20 -0700 (PDT), wrote: Anyone know the approximate resistance of the strip? Some photos of the insides of an 8024a, which is fairly close in construction to an 8060a. http://www.eevblog.com/forum/testgear/fluke-8024b-33-years-old-and-still-going-strong!-beware-3mb-photos/ The ribbon cable: http://s193.photobucket.com/user/Bl4ckW0lfi3/media/Fluke8024B-09_zps4b433951.jpg.html The ribbon cable between the two boards is made from screened graphite, which tends to crack if flexed. I found a similar ribbon cable, but made from flattened copper wire that looked more reliable. I removed the original ribbon cable, clamped in the new cable, and after a bit of jiggling, got it to make a connection without soldering. Once it was working, I used hot melt glue to hold it in place. I suppose soldering would have been easier, but at the time, I didn't want to wreck the meter. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 Other than the shape of the boards, they're not much alike. The 8060 has no flexible membrane circuit. For the heck of it, I took a straight edge and a sharp razor and removed about a 16th from both sides of the rubber conductive strip, and still no continuity whatsoever, so I hard wired the display. It now starts, boots, and passes the power up test. The display is clear and has full contrast. The problem is that it's reading voltages and resistances that don't exist, even though it does read my test voltages and resistances. I guess I have to take this apart again and do a better job of cleaning the electrolyte off the board. The link posted by an earlier poster shows problems with leakage below the main chip/socket only. If I knew that would be the only problem to address, I'd pull the socket and try it. The problem is is that every individual solution requires undoing the display hardwire, so I'm trying to formulate a plan to effectively clean this in one shot. John John |
#7
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Fluke 8060a meter interconnect strip
On Sunday, May 1, 2016 at 5:53:42 PM UTC-4, Jeff Liebermann wrote:
On Sun, 1 May 2016 12:41:20 -0700 (PDT), wrote: Anyone know the approximate resistance of the strip? Some photos of the insides of an 8024a, which is fairly close in construction to an 8060a. http://www.eevblog.com/forum/testgear/fluke-8024b-33-years-old-and-still-going-strong!-beware-3mb-photos/ The ribbon cable: http://s193.photobucket.com/user/Bl4ckW0lfi3/media/Fluke8024B-09_zps4b433951.jpg.html The ribbon cable between the two boards is made from screened graphite, which tends to crack if flexed. I found a similar ribbon cable, but made from flattened copper wire that looked more reliable. I removed the original ribbon cable, clamped in the new cable, and after a bit of jiggling, got it to make a connection without soldering. Once it was working, I used hot melt glue to hold it in place. I suppose soldering would have been easier, but at the time, I didn't want to wreck the meter. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 Other than the shape of the boards, the 8026 and 8060 are not much alike. The 8060 has no flexible membrane circuit. For the heck of it, I took a straight edge and a sharp razor and removed about a 16th from both sides of the rubber conductive strip, and still no continuity whatsoever, so I hard wired the display. It now starts, boots, and passes the power up test. The display is clear and has full contrast. The problem is that it's reading voltages and resistances that don't exist, even though it does read my test voltages and resistances. I guess I have to take this apart again and do a better job of cleaning the electrolyte off the board. The link posted by an earlier poster shows problems with leakage below the main chip/socket only. If I knew that would be the only problem to address, I'd pull the socket and try it. The problem is is that every individual solution requires undoing the display hardwire, so I'm trying to formulate a plan to effectively clean this in one shot. John |
#8
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Fluke 8060a meter interconnect strip
On Monday, May 2, 2016 at 11:39:00 AM UTC-4, wrote:
The link posted by an earlier poster shows problems with leakage below the main chip/socket only. If I knew that would be the only problem to address, I'd pull the socket and try it. The problem is is that every individual solution requires undoing the display hardwire, so I'm trying to formulate a plan to effectively clean this in one shot. John I pulled the main IC/socket and there's no sign of leakage on or under the socket pins or board. The capacitor leakage seems to be contained under the switch assy. I removed three variable caps which hugged the board and removed the power switch. Every other part is either high enough off the board not to be touched by a very shallow bath or would not be unaffected by one. Next plan is to give it a hot shallow bath of distilled water followed by a wash of IPA and a few hours in the hot box. I have other things on my bench right now so I won't play any more with this for a few days at least. John |
#9
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Fluke 8060a meter interconnect strip *update working-- sorta*
On Mon, 2 May 2016 08:37:14 -0700 (PDT), wrote:
Other than the shape of the boards, they're not much alike. The 8060 has no flexible membrane circuit. Oops. I couldn't find any decent 8060a photos other than the repair article, so I guessed that they were the same from memory. Sorry for the misinformation. http://mrmodemhead.com/blog/fluke-8060a-repair/ The problem is that it's reading voltages and resistances that don't exist, even though it does read my test voltages and resistances. I guess I have to take this apart again and do a better job of cleaning the electrolyte off the board. The link posted by an earlier poster shows problems with leakage below the main chip/socket only. If I knew that would be the only problem to address, I'd pull the socket and try it. The problem is is that every individual solution requires undoing the display hardwire, so I'm trying to formulate a plan to effectively clean this in one shot. Well, I may join you on this repair. I just found my long lost Fluke 8060a. About +1.5mv of residual reading on the 200mv scale. I'll drag it to my office, take some photos, and measure the Zebra strip resistance for you (probably tomorrow). Meanwhile, this might offer a clue as to the resistance; https://en.wikipedia.org/wiki/Elastomeric_connector http://www.fujipoly.com/usa/design-guidelines/89.html Unrelated dumb question. The three case screws for this Fluke 8060A seem to have walked away. What's the thread designation so I can buy some replacements? There's plenty similar screws on eBay: http://www.ebay.com/sch/i.html?_nkw=fluke+screws but none specifically for the 8000 series DMM. $1.50/ea including shipping. I'll probably do better at the hardware store Never mind. I found the type in the user manual on Pg 6-5 in: http://assets.fluke.com/manuals/8060a_3vimeng0200.pdf SCREW,PH,P,THD FORM,STL,7-19,.750 -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#10
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Fluke 8060a meter interconnect strip *update working-- sorta*
On Monday, May 2, 2016 at 2:14:13 PM UTC-4, Jeff Liebermann wrote:
Never mind. I found the type in the user manual on Pg 6-5 in: http://assets.fluke.com/manuals/8060a_3vimeng0200.pdf SCREW,PH,P,THD FORM,STL,7-19,.750 You lost the screws, somewhere along the way I lost one of the push buttons. Too bad I can't get one of those in a hardware store! John |
#11
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Fluke 8060a meter interconnect strip *update working-- sorta*
On Mon, 2 May 2016 13:57:02 -0700 (PDT), wrote:
On Monday, May 2, 2016 at 2:14:13 PM UTC-4, Jeff Liebermann wrote: Never mind. I found the type in the user manual on Pg 6-5 in: http://assets.fluke.com/manuals/8060a_3vimeng0200.pdf SCREW,PH,P,THD FORM,STL,7-19,.750 You lost the screws, I several large candy jars that are full of random hardware. I probably tossed the screws in one of them. It's easier to buy replacements than to excavate them from the jars. Needle in haystack. The local Ace hardware store didn't have any plastic screws. somewhere along the way I lost one of the push buttons. Too bad I can't get one of those in a hardware store! You can get another carcass on eBay. Or buy one from the test equipment cannibals: http://www.ebay.com/sch/i.html?_nkw=fluke+dvm+switch+cover Notice that the LCD display is starting to turn black along the bottom edge. Most of my various Fluke meters have the same problem. I tore my 8050a apart and tooks some photos and measurements: http://802.11junk.com/jeffl/pics/Fluke%208060a/ This Zebra strip measures about 1K ohms: http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-8060a-LCD-1.jpg while this one measures about 5 ohms: http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-8060a-LCD-2.jpg Measuring the resistance was a PITA. The problem was determining whether I was measuring the resistance of one contact, or a bunch of them in parallel. I didn't want to drag out the microscope, so I resorted to a trick. I placed the flat side of one DVM probe across a section of the strip so that it would connect to a large number of conductive strips. I then used a very sharp needle tip to make contact on the other side. It wasn't perfect, but I think it was good enough. More photos when I have time. Anything else you want photographed or measured? -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#12
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Fluke 8060a meter interconnect strip *update working-- sorta*
On Mon, 02 May 2016 11:14:14 -0700, Jeff Liebermann
wrote: Well, I may join you on this repair. I just found my long lost Fluke 8060a. About +1.5mv of residual reading on the 200mv scale. I'll drag it to my office, take some photos, and measure the Zebra strip resistance for you (probably tomorrow). Curses, foiled again. While tearing apart the meter, taking photos, and putting it back together, I managed to transfer enough blood, sweat, and tears onto the PCB and components to wreck the calibration and add some more leakage. Instead of +1.5mv of residual junk on the 200mv scale, I now have about -7mv of leakage. The next time I work on this meter, I'll remember to use latex or nitrile gloves. 90% alcohol and bake dry scheduled for next weekend. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#13
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Fluke 8060a meter interconnect strip *update working-- sorta*
On Monday, May 2, 2016 at 9:06:34 PM UTC-4, Jeff Liebermann wrote:
This Zebra strip measures about 1K ohms: http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-8060a-LCD-1.jpg while this one measures about 5 ohms: http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-8060a-LCD-2.jpg Measuring the resistance was a PITA. The problem was determining whether I was measuring the resistance of one contact, or a bunch of them in parallel. The conductors are *very* dense in this particular zebra strip and I'd guess that there's at a minimum 10 conductors presented across the large pads on the boards they make contact with, so I'd venture that if they're 5 ohms each and 10 or more are paralleled across the pads, a wire jumper is just fine. More photos when I have time. Anything else you want photographed or measured? Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 No, I think I'm OK at this point. After it takes it's IPA bath I'll reassemble and see where I'm at. Thanks for the information! If the meter turns out OK, I'll probably pick up a DOA meter on ebay for parts, including the missing button. If the meter still is a bit wonky, I'll remove the switch pack and give it an ultrasonic bath. The bottom of my display looks exactly like yours. Are you sure this is abnormal? The bottom edge is where the round zebra strip contacts the LCD electrically on the back side, so maybe that thicker area is normal. The border around the entire LCD display is black although much thinner. John |
#14
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Fluke 8060a meter interconnect strip *update working-- sorta*
On Tue, 3 May 2016 04:46:25 -0700 (PDT), wrote:
On Monday, May 2, 2016 at 9:06:34 PM UTC-4, Jeff Liebermann wrote: This Zebra strip measures about 1K ohms: http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-8060a-LCD-1.jpg while this one measures about 5 ohms: http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-8060a-LCD-2.jpg Measuring the resistance was a PITA. The problem was determining whether I was measuring the resistance of one contact, or a bunch of them in parallel. The conductors are *very* dense in this particular zebra strip and I'd guess that there's at a minimum 10 conductors presented across the large pads on the boards they make contact with, so I'd venture that if they're 5 ohms each and 10 or more are paralleled across the pads, a wire jumper is just fine. Yep. I can measure the resistance from PCB pad to pad in that area if you want. However, it will need to wait a few days. Bizzeee. I had quite a struggle reassembling the LCD display. The LCD glass fits into a slot of sorts in the plastic frame that requires the Zebra strip to be compressed. Insert just the glass LCD plate first and use brute force to compress the Zebra strip. Then, slide in the plastic screen protector and frame. If anyone has a better way, I would be interested. After it takes it's IPA bath I'll reassemble and see where I'm at. Thanks for the information! The article at: http://mrmodemhead.com/blog/fluke-8060a-repair/ (near the bottom) says to let it dry for a few hours after an alcohol bath. I've had the same experience. Alcohol absorbs moisture from the air and will dump this moisture onto the PCB during cleaning. It takes a while to evaporate. If the meter turns out OK, I'll probably pick up a DOA meter on ebay for parts, including the missing button. If the meter still is a bit wonky, I'll remove the switch pack and give it an ultrasonic bath. I've destroyed a few two-way radios using a 10 watt ultrasonic cleaner. It tends to kill semiconductor devices with unsupported wire bonds to the chip. I suggest using a brush instead. A brush doesn't get under IC sockets and overhanging components, so I like flood the area with alcohol, let it sit for about 30 seconds, and blow it out with compressed air. Not the best way, but better than shaking the meter to death. I haven't done too many DVM's so I don't know what a solvent bath will do the rotary switch. The bottom of my display looks exactly like yours. Are you sure this is abnormal? The bottom edge is where the round zebra strip contacts the LCD electrically on the back side, so maybe that thicker area is normal. The border around the entire LCD display is black although much thinner. No, I'm not sure. My eyesight isn't that great any more. I've seen a much more extreme black edge smear on other Fluke LCD displays. Here's an 8020A display disassembled: http://s1259.photobucket.com/user/mrmodemhead/media/Fluke%208020B/F8020B_018.jpg.html It has a black border, but it's very different from the 8060a: http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-8060a-LCD-1.jpg You might be right as the black line seems rather consistent instead of the creeping black blob caused by case leakage. I'll put it under the microscope later and double check. This is what it *MIGHT* look like eventually: http://www.vintage-radio.net/forum/attachment.php?attachmentid=31080&d=1260895739 http://www.eevblog.com/forum/chat/recovery-of-an-old-fluke-8020a-with-a-bad-lcd/?action=dlattach;attach=5445 http://www.eevblog.com/forum/chat/just-got-my-'new'-multimeter-the-family-become-larger/?action=dlattach;attach=1305;image Still looking for the missing case screws. No luck so far. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#15
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Fluke 8060a meter interconnect strip
On Sunday, May 1, 2016 at 3:41:23 PM UTC-4, wrote:
I have an old IBM labelled Fluke built DMM (8060a equivalent) that hasn't worked in years for reasons I don't recall exactly, but seem to think it was stone dead. I had it apart and left in a box and, since my last 87 crapped out a few weeks ago, I needed the low ohms feature of one or the other so I took another look at the old IBM. I found just about every electrolytic on the board physically leaky, and most down in value and ESR, some considerably. I replaced them all but when assembling the meter, I checked the two flexible rubber interconnect strips. One of them is round and reads zero ohms all across it's length, so that one's good. The other is a flat rectangular piece, and I cannot get any kind of resistance reading *anywhere* across it. I've cleaned it several times including using an abrasive last time and cannot get a whiff of conductance, and I've put considerable pressure on the test leads. I guess it being unassembled and sitting in free air must have poisoned it somehow as I don't recall it having any issues with erratic segments before the meter died. It will be easy to hard wire this but was wondering if this is a low ohm transfer strip of something maybe a few ohms to a few thousand. If it's low ohms, I'll just hard wire it. If it's something other, there's plenty of room to put in 1/8 w resistors of appropriate value. Anyone know the approximate resistance of the strip? I removed the switch assy, the main IC socket, and the variable capacitors from the board. Several rounds of 91% IPA bathing has not cleaned the sticky electrolyte off the board, except where I could get an acid brush in to scrub. Two remaining options are to remove every other part off the board and scrub with a fiber brush or go to a more aggressive cleaner. I'm going with option two and see what happens. John |
#16
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Fluke 8060a meter interconnect strip
On Wed, 4 May 2016 10:23:09 -0700 (PDT), wrote:
I removed the switch assy, the main IC socket, and the variable capacitors from the board. Several rounds of 91% IPA bathing has not cleaned the sticky electrolyte off the board, except where I could get an acid brush in to scrub. Two remaining options are to remove every other part off the board and scrub with a fiber brush or go to a more aggressive cleaner. I'm going with option two and see what happens. John Older electrolytic capacitors used ethylene glycol and boric acid for electrolyte. Later versions used dimethylformamide, dimethylacetamide, or butyrolactone. If you look these up on Wikipedia, the table on the right includes solubility: https://en.wikipedia.org/wiki/Ethylene_glycol https://en.wikipedia.org/wiki/Dimethylacetamide https://en.wikipedia.org/wiki/Dimethylformamide https://en.wikipedia.org/wiki/Gamma-Butyrolactone I would try detergent and water first, followed by a distilled or deoinized water rinse. If that fails, start up the ladder of chlorinated hydrocarbon solvents, starting with alcohol. I wouldn't go much past trichlorethane or trichlorethylene which will probably peel off the PCB printing, labels, and maybe the silk screening. Some of these will also attack the epoxy that holds the PCB together. Be careful and good luck. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#17
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Fluke 8060a meter interconnect strip
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#18
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Fluke 8060a meter interconnect strip
On Wednesday, May 4, 2016 at 2:59:17 PM UTC-4, Jeff Liebermann wrote:
On Wed, 4 May 2016 10:23:09 -0700 (PDT), wrote: I removed the switch assy, the main IC socket, and the variable capacitors from the board. Several rounds of 91% IPA bathing has not cleaned the sticky electrolyte off the board, except where I could get an acid brush in to scrub. Two remaining options are to remove every other part off the board and scrub with a fiber brush or go to a more aggressive cleaner. I'm going with option two and see what happens. John Older electrolytic capacitors used ethylene glycol and boric acid for electrolyte. Later versions used dimethylformamide, dimethylacetamide, or butyrolactone. If you look these up on Wikipedia, the table on the right includes solubility: https://en.wikipedia.org/wiki/Ethylene_glycol https://en.wikipedia.org/wiki/Dimethylacetamide https://en.wikipedia.org/wiki/Dimethylformamide https://en.wikipedia.org/wiki/Gamma-Butyrolactone I would try detergent and water first, followed by a distilled or deoinized water rinse. If that fails, start up the ladder of chlorinated hydrocarbon solvents, starting with alcohol. I wouldn't go much past trichlorethane or trichlorethylene which will probably peel off the PCB printing, labels, and maybe the silk screening. Some of these will also attack the epoxy that holds the PCB together. Be careful and good luck. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 That makes a lot of sense. As I was unsoldering all the leaky caps, I never once got a whiff of low tide. When I was rebuilding Sony and Canon camcorders in the 90s most of them needed 40 or 50 smd caps, and my bench smelled like catch of the day. Clearly the formulation is different for the caps in the Flukes from what we see nowadays. Anyway, your advice to avoid ultrasonic cleaners made way too much sense so I went ahead and soaked the board with my favorite circuit board cleaner; Fantastik. After a few soaks and rinses, the board looks, well, fantastic. It's clean as a whistle and all the goo is gone, including the crap under the inline packages and ICs. I rinsed in distilled water and now it's getting it's last IPA bath. I'll let it dry and reassemble in a few days and hope for the best. And if that's your ground mail, I can send you two screws I have off a non-working 85 that I think needs a main chip. This meter crapped about 8 years ago and I misplaced one of the screws, but if you want the other two, they're yours. I'm on the east coast so it'll be a week. John |
#19
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Fluke 8060a meter interconnect strip
On Wed, 4 May 2016 15:07:53 -0700 (PDT), wrote:
That makes a lot of sense. As I was unsoldering all the leaky caps, I never once got a whiff of low tide. When I was rebuilding Sony and Canon camcorders in the 90s most of them needed 40 or 50 smd caps, and my bench smelled like catch of the day. Clearly the formulation is different for the caps in the Flukes from what we see nowadays. Yep. Lots of changes in electrolyte. I really don't know what Fluke was using. Anyway, your advice to avoid ultrasonic cleaners made way too much sense so I went ahead and soaked the board with my favorite circuit board cleaner; Fantastik. Ugh. I use Formula 409. I had some issues with Fantastik leaving some residue that didn't evaporate. Fortunately, most seemed to wash off with deionized water, so it wasn't fatal. Residue was easy enough to detect by leaving a blob of Fantastik on a microscope slide, let it evaporate, and inspect the bathtub ring. There wasn't much, but there was enough to make me worry. Fantastik has changed their formulation over the years. This should be the latest (Formula 35*19431): http://www.whatsinsidescjohnson.com/us/en/brands/fantastik/fantastik-mini-concentrated-kitchen-cleaner I have a small problem with the oily fragrance, which does evaporate, but very slowly. The stabilizer and dye also might leave a residue, but I'm not sure. Both 409 and Fantastik are highly alkaline (pH=10.5 to 11.5), which should not be a problem. The grease was cleaned by the inclusion of ethyl alcohol. After a few soaks and rinses, the board looks, well, fantastic. It's clean as a whistle and all the goo is gone, including the crap under the inline packages and ICs. I rinsed in distilled water and now it's getting it's last IPA bath. I'll let it dry and reassemble in a few days and hope for the best. Sounds good. Check the residual voltage displayed on the 200mv scale to see if the PCB is still leaking. I know mine is leaking from all my unprotected handling. And if that's your ground mail, I can send you two screws I have off a non-working 85 that I think needs a main chip. This meter crapped about 8 years ago and I misplaced one of the screws, but if you want the other two, they're yours. I'm on the east coast so it'll be a week. Thanks. The address is my palatial office. I could use the screws to finish my 8060A. However, if you think you're going to eventually fix the Model 85, I suggest you keep them. I'll eventually find where I misplaced my screws or find replacements. Also, I'm still not sure about the black line at the bottom of the LCD. However, I'm inclined to believer that you're correct and that mine is normal. When reassembled, the screen does not show the black line and everything else looks normal. -- 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
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Fluke 8060a meter interconnect strip
On Wed, 4 May 2016 17:59:53 -0400, Ralph Mowery
wrote: I have seen references to mixing IPA and acetone 50/50 to do some PC board cleaning. Any thing good or bad about doing that ? No. Bad idea. Don't do that. Acetone will attack many plastics (ABS, polycarbonate, polystyrene, polyethylene, vinyl, etc). Before you use ANY manner of solvent, do some research on a "chemical compatibility chart" for the materials you expect to be using. https://capolight.files.wordpress.com/2010/08/solvent_compatibility.jpg Be sure to check compatibility with epoxy, as that's what the PCB is made from. For example: http://www.coleparmer.com/Chemical-Resistance shows that: ABS plastic and acetone = "Severe Effect" ABS plastic and 50% acetone and water = "Severe Effect" Also, I guess I should mention that there are many different types of alcohols (amyl, benzyl, butyl, diacetone, ethyl, hexyl, ibsbutyl, methyl, octyl, propyl, etc). Characteristics vary so don't assume that some random alcohol is safe just because isopropyl alcohol didn't destroy some plastic. I had to learn that lesson when I switched to the "alcohol" sold by the local hardware store, and found it far more aggressive than the 91% drug store variety. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#21
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Fluke 8060a meter interconnect strip
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#22
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Fluke 8060a meter interconnect strip
On Wednesday, May 4, 2016 at 8:15:26 PM UTC-4, Jeff Liebermann wrote:
I could use the screws to finish my 8060A. However, if you think you're going to eventually fix the Model 85, I suggest you keep them. I'll eventually find where I misplaced my screws or find replacements. The 85 has a bad p channel jfet sot23 and I've had a problem locating one, so I put the meter aside. But some time before it crapped, the sounder would squawk for no reason so something else was going on with it. I isolated the sounder for the last year I used it. Also, the terminal blocks on these are crap and this one was breaking up, so I retired it. John |
#23
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Fluke 8060a meter interconnect strip
On Wed, 4 May 2016 15:07:53 -0700 (PDT), wrote:
And if that's your ground mail, I can send you two screws I have off a non-working 85 that I think needs a main chip. This meter crapped about 8 years ago and I misplaced one of the screws, but if you want the other two, they're yours. I'm on the east coast so it'll be a week. John Thanks. Got the screws today. They fit nicely in the 8060A. However, there's a bit of an oddity here. http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-screws.jpg The Model 85 screws fit in the 8060A, but the original screws (as borrowed from an 8024A) are a bit different. Notice the double spiral, the different pitch, and that the 8024a screw is a bit larger diameter. Which style does your 8060A use? Incidentally, when I removed the 40 pin chip from its socket, I found that some of the socket contacts had gotten wet and started to corrode. I've also got an offset on most scales thanks to leakage across the PCB. Looks like I'll be replacing the socket with something better, and giving the PCB an alcohol rubdown. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#24
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Fluke 8060a meter interconnect strip
On Wednesday, May 11, 2016 at 11:30:18 PM UTC-4, Jeff Liebermann wrote:
On Wed, 4 May 2016 15:07:53 -0700 (PDT), wrote: And if that's your ground mail, I can send you two screws I have off a non-working 85 that I think needs a main chip. This meter crapped about 8 years ago and I misplaced one of the screws, but if you want the other two, they're yours. I'm on the east coast so it'll be a week. John Thanks. Got the screws today. They fit nicely in the 8060A. However, there's a bit of an oddity here. http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-screws.jpg The Model 85 screws fit in the 8060A, but the original screws (as borrowed from an 8024A) are a bit different. Notice the double spiral, the different pitch, and that the 8024a screw is a bit larger diameter. Which style does your 8060A use? The screws from my IBM 8060A are the double helix. The screws I sent you did not actually come from my 85, but from a newer 77. When asking around if anyone had any dead Flukes (trying to locate that p-jfet for my 85), I was given a 77 that was blasted by a microwave oven. The 77 didn't have the jfet I needed so I ended up fixing the 77 and returning it to the donator as a gift, but not before swapping the screws with some generic screws I had as payment . Those I sent to you because there were three and I only had two from the 85. Whew! Incidentally, when I removed the 40 pin chip from its socket, I found that some of the socket contacts had gotten wet and started to corrode. I've also got an offset on most scales thanks to leakage across the PCB. Looks like I'll be replacing the socket with something better, and giving the PCB an alcohol rubdown. When I removed the chip from the socket, I found there was no corrosion evident but two of the tangs in the socket came apart, so I ordered a new socket and put the repair on hold until it arrives. John |
#25
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Fluke 8060a meter interconnect strip
On Thu, 12 May 2016 08:15:45 -0700 (PDT), wrote:
On Wednesday, May 11, 2016 at 11:30:18 PM UTC-4, Jeff Liebermann wrote: On Wed, 4 May 2016 15:07:53 -0700 (PDT), wrote: And if that's your ground mail, I can send you two screws I have off a non-working 85 that I think needs a main chip. This meter crapped about 8 years ago and I misplaced one of the screws, but if you want the other two, they're yours. I'm on the east coast so it'll be a week. John Thanks. Got the screws today. They fit nicely in the 8060A. However, there's a bit of an oddity here. http://802.11junk.com/jeffl/pics/Fluke%208060a/Fluke-screws.jpg The Model 85 screws fit in the 8060A, but the original screws (as borrowed from an 8024A) are a bit different. Notice the double spiral, the different pitch, and that the 8024a screw is a bit larger diameter. Which style does your 8060A use? The screws from my IBM 8060A are the double helix. Thanks. Those are almost impossible to find. I think it's a #7-19 3/4" High Low Thread Forming Screw. Digging: http://www.eaglefastener.net/technical/hilo-fastener-table.html My digital calipers claims it's a #7-19 and 19 tpi which seems about right. Nothing on eBay. I can't seem to find any that I can order, but will continue digging. I also need to verify the size, which seems rather odd. The screws I sent you did not actually come from my 85, but from a newer 77. Sigh. So I have to change my JPG again. Grumble(tm). When asking around if anyone had any dead Flukes (trying to locate that p-jfet for my 85), If I have time, I'll try to identify the JFET for the Model 85. What is the reference designator so I know which one? I was given a 77 that was blasted by a microwave oven. I just can't resist the temptation. What the [deleted explitive] was someone thinking when they put the DVM in the oven? Is this the same person that tried to dry their poodle in the micrwave? The 77 didn't have the jfet I needed so I ended up fixing the 77 and returning it to the donator as a gift, but not before swapping the screws with some generic screws I had as payment . Nicely done. Those I sent to you because there were three and I only had two from the 85. Whew! Thanks again. I have about 5 assorted Fluke meters scattered around. Most are held together with one screw and a rubber band. Most are the older models, which take the high-low thread forming screws. I hadn't planned on doing this for a while, but I guess now that I've started, it's time to replace the missing parts, fix any battle damage, clean the crud out of the guts, and calibrate the meters. When I removed the chip from the socket, I found there was no corrosion evident but two of the tangs in the socket came apart, so I ordered a new socket and put the repair on hold until it arrives. I have a bunch of these, which methinks will work (after I check the height). I had the same problem with the existing socket. Where the corrosive goo from the electrolytic or water rotted out the socket, one of the contacts fell out. However, I cleaned the other contact, which still works... for now. I guess I should stock up on replacment electrolytics and just do a pre-emptive replacement. Sigh, the project grows. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
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