Hi,

I have a Dell Optiplex SX260 small desktop type computer that won't
boot up. When I press the power button, there is no display on monitor, no
HDD spin up noise. The only "life" I see/hear is the power light comes on and
the fans run. I tried a bootable CD, but the CD drive doesn't "run".

Note: I protected against static damage using a ground strap to my body.

I checked all the on board fuses (all good), solder joints, and power
supply output voltages with a load. The CMOS (RTC) battery is good.
I even removed and reinstalled the CPU.

Did anyone have the same problem with this model computer?

Thank You in advance, John

No POST beeps or light codes?
If it is using a separate graphics card, remove and/or substitute.
Try different RAM.

wrote in message
...
Hi,

I have a Dell Optiplex SX260 small desktop type computer that won't
boot up. When I press the power button, there is no display on monitor,
no
HDD spin up noise. The only "life" I see/hear is the power light comes on
and
the fans run. I tried a bootable CD, but the CD drive doesn't "run".

Note: I protected against static damage using a ground strap to my
body.

I checked all the on board fuses (all good), solder joints, and power
supply output voltages with a load. The CMOS (RTC) battery is good.
I even removed and reinstalled the CPU.

Did anyone have the same problem with this model computer?

Thank You in advance, John

wrote:

Hi,

I have a Dell Optiplex SX260 small desktop type computer that won't
boot up. When I press the power button, there is no display on monitor, no
HDD spin up noise. The only "life" I see/hear is the power light comes on and
the fans run. I tried a bootable CD, but the CD drive doesn't "run".

Note: I protected against static damage using a ground strap to my body.

I checked all the on board fuses (all good), solder joints, and power
supply output voltages with a load. The CMOS (RTC) battery is good.
I even removed and reinstalled the CPU.

Did anyone have the same problem with this model computer?

Thank You in advance, John



Bad electrolytics.

John Keiser wrote:

No POST beeps or light codes?
If it is using a separate graphics card, remove and/or substitute.
Try different RAM.


I have two of these computers. Onboard video, uses DDR2 RAM:
PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V • 128Meg x 64
It should boot on a single module.

This model is well known for bad electrolytics. So much so that a
kit is offered for it: http://www.thecapking.com/gx620sff.html

http://www.thecapking.com/index.html for other kits, or good prices
on low ESR caps for motherboards. I've bought from them and will again,
in the future.

Also, they small power supplies fail more often than power supplies
in larger systems. Some of those are just bad electrolytics, as well.

On Thu, 14 Feb 2013 10:29:13 -0500, wrote:

I have a Dell Optiplex SX260 small desktop type computer that won't
boot up.

Bulging capacitors on the motherboard. Probably nothing wrong with
the DA-1 external power supply, but it would a good idea to check if
you're getting 12VDC on the output. Also, put a scope on the 12V PS
output and look for noise. So far, I haven't found any bad power
supplies, but I've fixed about five of the SX260/270 boxes with bad
caps on the MB. It's not horribly difficult to replace the caps, but
it's tedious. Also, getting the motherboard out of the case is a bit
of a challenge around the rear panel green locking mechanism.

If you don't mind the shotgun approach, try a rebuild kit.
http://www.thecapking.com/sx260.html
http://www.ebay.com/itm/290339293027
http://www.ebay.com/itm/130683253583
etc...

Hint: The fastest CPU that will work in the SX260 is 2.8GHz with
hyperthreading.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Thu, 14 Feb 2013 13:24:03 -0500, "Michael A. Terrell"
wrote:

I have two of these computers.

I have three of them. However, only one works and I only have one
power supply. The other two are waiting for time to fix, or recycling
(toss a coin).

This model is well known for bad electrolytics. So much so that a
kit is offered for it: http://www.thecapking.com/gx620sff.html

http://www.thecapking.com/index.html for other kits, or good prices
on low ESR caps for motherboards. I've bought from them and will again,
in the future.

I replace enough caps to justify buying 25, 50, or 100 at a time.
http://802.11junk.com/jeffl/pics/repair/bad-caps.jpg

Also, they small power supplies fail more often than power supplies
in larger systems. Some of those are just bad electrolytics, as well.

Huh? I haven't seen any of the external 12V power supplies that have
failed. I think I've gone through about 8 of them so far, mostly used
on a previous generation of weather stations. I've been tempted to
see what range of voltage the SX260 will operate. I want to put it on
a storage battery and charger system, which means anything between
11.0 and 16.0VDC. Have you ever tried it? (I don't want to risk
blowing up my last remaining SX260 machine).


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Thursday, February 14, 2013 7:29:13 AM UTC-8, wrote:
Hi, I have a Dell Optiplex SX260 small desktop type computer that won't boot up. When I press the power button, there is no display on monitor, no HDD spin up noise. The only "life" I see/hear is the power light comes on and the fans run. I tried a bootable CD, but the CD drive doesn't "run". Note: I protected against static damage using a ground strap to my body. I checked all the on board fuses (all good), solder joints, and power supply output voltages with a load. The CMOS (RTC) battery is good. I even removed and reinstalled the CPU. Did anyone have the same problem with this model computer? Thank You in advance, John

I think that instead of thinking about this as a Dell computer problem, you might look at the problem as what would cause *any* desktop to not boot. It's been a long while since I've knocked together desktop computers, but when one didn't boot it was because of simple things like conflicting cards, or even a
keyboard problem. Checkout this

http://pcsupport.about.com/od/findby...nt-turn-on.htm

for some really good troubleshooting tips.

Ron

Jeff Liebermann wrote:

On Thu, 14 Feb 2013 13:24:03 -0500, "Michael A. Terrell"
wrote:

I have two of these computers.

I have three of them. However, only one works and I only have one
power supply. The other two are waiting for time to fix, or recycling
(toss a coin).


I can only find one right now, and didn't think it was worth
repairing. The hard drive & CDROm drive are now missing, and it had no
bulging or leaking caps. Since I repair the computers to give away, it
doesn't make much sense to spend money & time on it. It was in the TBPO
pile.


This model is well known for bad electrolytics. So much so that a
kit is offered for it: http://www.thecapking.com/gx620sff.html

http://www.thecapking.com/index.html for other kits, or good prices
on low ESR caps for motherboards. I've bought from them and will again,
in the future.

I replace enough caps to justify buying 25, 50, or 100 at a time.
http://802.11junk.com/jeffl/pics/repair/bad-caps.jpg


I buy most 100 at a time, too.


Also, the small power supplies fail more often than power supplies
in larger systems. Some of those are just bad electrolytics, as well.

Huh? I haven't seen any of the external 12V power supplies that have
failed. I think I've gone through about 8 of them so far, mostly used
on a previous generation of weather stations. I've been tempted to
see what range of voltage the SX260 will operate. I want to put it on
a storage battery and charger system, which means anything between
11.0 and 16.0VDC. Have you ever tried it? (I don't want to risk
blowing up my last remaining SX260 machine).


Why not use a switching converter that boosts then bucks the voltage
so you can run it anywhere you want. I'm currently working on a 12 to
90 volt converter design for run antique radios from a Lead acid, NiMh
or NiCad battery pack in the 8 to 16 volt range. I had fun finding
reasonably priced feedthrough caps, and will have to hand wind the
transformers. I need to keep the EMI down so it won't bother the radio
on weak signals.

On Thu, 14 Feb 2013 22:31:44 -0500, "Michael A. Terrell"
wrote:

Huh? I haven't seen any of the external 12V power supplies that have
failed. I think I've gone through about 8 of them so far, mostly used
on a previous generation of weather stations. I've been tempted to
see what range of voltage the SX260 will operate. I want to put it on
a storage battery and charger system, which means anything between
11.0 and 16.0VDC. Have you ever tried it? (I don't want to risk
blowing up my last remaining SX260 machine).

Why not use a switching converter that boosts then bucks the voltage
so you can run it anywhere you want.

I could use a 12v to 12v DC to DC converter to deal with the input
range. However, these weather stations are mostly on mountain top
radio sites, where the switching noise would not be welcome. I've had
problems with this in the past and would like to avoid it. We have a
perfectly good 12V battery based system running the stuff that will
run on 12VDC, which is most everything these days. I just wanted to
add the SX260 to the 12V battery bus. The only problem is not knowing
the range of voltages it will tolerate. I guess I'll have to
sacrifice an SX260 or SX280 and see what blows up. (I've failed to
find schematics).

I'm currently working on a 12 to
90 volt converter design for run antique radios from a Lead acid, NiMh
or NiCad battery pack in the 8 to 16 volt range.

Well, there are battery eliminators for such radios, but they mostly
run on 117VAC.

I had fun finding
reasonably priced feedthrough caps, and will have to hand wind the
transformers. I need to keep the EMI down so it won't bother the radio
on weak signals.

Yeah, that's the killer. I have the stock 12V to 117VAC converter
that bolts onto the back of my Wavetek 3000B service monitor. Running
on 12VDC, it generates enough noise to make the receiver in the
service monitor useless for anything except very strong signals.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:

On Thu, 14 Feb 2013 22:31:44 -0500, "Michael A. Terrell"
wrote:

Huh? I haven't seen any of the external 12V power supplies that have
failed. I think I've gone through about 8 of them so far, mostly used
on a previous generation of weather stations. I've been tempted to
see what range of voltage the SX260 will operate. I want to put it on
a storage battery and charger system, which means anything between
11.0 and 16.0VDC. Have you ever tried it? (I don't want to risk
blowing up my last remaining SX260 machine).

Why not use a switching converter that boosts then bucks the voltage
so you can run it anywhere you want.

I could use a 12v to 12v DC to DC converter to deal with the input
range. However, these weather stations are mostly on mountain top
radio sites, where the switching noise would not be welcome. I've had
problems with this in the past and would like to avoid it. We have a
perfectly good 12V battery based system running the stuff that will
run on 12VDC, which is most everything these days. I just wanted to
add the SX260 to the 12V battery bus. The only problem is not knowing
the range of voltages it will tolerate. I guess I'll have to
sacrifice an SX260 or SX280 and see what blows up. (I've failed to
find schematics).


I have one dead 260 I'm not going to bother with. I'd givve it to
you, but shipping from Florida is probably more than it's worth.


I'm currently working on a 12 to
90 volt converter design for run antique radios from a Lead acid, NiMh
or NiCad battery pack in the 8 to 16 volt range.

Well, there are battery eliminators for such radios, but they mostly
run on 117VAC.


The radios I'm interested in will play on 117 AC or DC as built.


I had fun finding
reasonably priced feedthrough caps, and will have to hand wind the
transformers. I need to keep the EMI down so it won't bother the radio
on weak signals.

Yeah, that's the killer. I have the stock 12V to 117VAC converter
that bolts onto the back of my Wavetek 3000B service monitor. Running
on 12VDC, it generates enough noise to make the receiver in the
service monitor useless for anything except very strong signals.


I learned a lot at Microdyne about filtering. People won't pay
$20,000 to $80,000 for a receiver that has internal noise problems.

On Fri, 15 Feb 2013 11:00:54 -0500, "Michael A. Terrell"
wrote:

I have one dead 260 I'm not going to bother with. I'd givve it to
you, but shipping from Florida is probably more than it's worth.

Thanks, but I don't think a dead computah is going to help. I need
to see if it will actually run on a range of DC voltages. I'll let
you know how it goes when and if I find time to play.

I learned a lot at Microdyne about filtering. People won't pay
$20,000 to $80,000 for a receiver that has internal noise problems.

Yep. Self-interference sucks but is all too common. My IFR-1500
service monitor has a built in 117VAC and 12VDC combination power
supply (single unit). I gave up on fixing the AC section and am
running it on DC. The switching noise isn't bad, but it's there. I
added some ferrite "beads" which made it usable.

You've probably seen these:
"Powering Your Antique Battery Radio"
http://antiqueradio.org/bsupply.htm
http://www.arbeiii.com

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:

On Fri, 15 Feb 2013 11:00:54 -0500, "Michael A. Terrell"
wrote:

I have one dead 260 I'm not going to bother with. I'd givve it to
you, but shipping from Florida is probably more than it's worth.

Thanks, but I don't think a dead computah is going to help. I need
to see if it will actually run on a range of DC voltages. I'll let
you know how it goes when and if I find time to play.

I learned a lot at Microdyne about filtering. People won't pay
$20,000 to $80,000 for a receiver that has internal noise problems.

Yep. Self-interference sucks but is all too common. My IFR-1500
service monitor has a built in 117VAC and 12VDC combination power
supply (single unit). I gave up on fixing the AC section and am
running it on DC. The switching noise isn't bad, but it's there. I
added some ferrite "beads" which made it usable.

You've probably seen these:
"Powering Your Antique Battery Radio"
http://antiqueradio.org/bsupply.htm

Yes. Philip Nelson was a regular on news:rec.antiques.radio+phono
for years.

http://www.arbeiii.com


That's another AC to DC supply. I want a rechargeable battery pack
with built in DC-DC converters for the 90 V plate & 9 V filament
supplies.


A lot of people do crap like this:

http://www.dialcover.com/batt1.jpg
http://www.dialcover.com/batt2.jpg
http://www.dialcover.com/zenbatt.jpg

Which is a 42 cent corregated paper mailer from www.Uline.com, and 10
dollar store grade 9 Volt batteries & 6 D cells for $42. They are on
this web page:


http://www.dialcover.com/components.html

BTW, Jeff Angus is back on a few newsgroups, but he can't access this
group most of the time. He is posting as Fox's Mercantile.

On Fri, 15 Feb 2013 16:12:12 -0500, "Michael A. Terrell"
wrote:

That's another AC to DC supply. I want a rechargeable battery pack
with built in DC-DC converters for the 90 V plate & 9 V filament
supplies.

I couldn't find a decent DC supply. Sorry.

http://www.dialcover.com/components.html

Bill Turner. I really like his "Cease and Desist" contact cleaner
formula.

How about 5VDC to 90VDC on a chip?
http://www.linear.com/product/LT3482
I did some Googling and found plenty of DC to DC inverters, but I'm
too busy (or lazy) to dig through the selection guides.

BTW, Jeff Angus is back on a few newsgroups, but he can't access this
group most of the time. He is posting as Fox's Mercantile.

Yeah, I know. Every time I screw up in this newsgroup, he sends me a
nasty email. Ocassionally, he agrees with me, which means I must have
really screwed up badly.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Jeff Liebermann wrote:

On Fri, 15 Feb 2013 16:12:12 -0500, "Michael A. Terrell"
wrote:

That's another AC to DC supply. I want a rechargeable battery pack
with built in DC-DC converters for the 90 V plate & 9 V filament
supplies.

I couldn't find a decent DC supply. Sorry.

http://www.dialcover.com/components.html

Bill Turner. I really like his "Cease and Desist" contact cleaner
formula.


He was claiming it was exactly the same as Deoxid, and got a cease &
desist letter from their lawyers. Then he claimed I called them to
report him. He wasn't worth a phone call. He's the Phil Allison of old
radioos. Foul mouthed & short tempered. he made claims that you could
make a LED flash with just a resistor & capacitor. That you could use a
1N34 diode in a line operated radio to replace a Selenium. He claimed
that a 1N4007 in series with a string of tubes dropped the voltage by
50% instead of the average power. You get the idea. He and Angus went
round & round on some issues.


How about 5VDC to 90VDC on a chip?
http://www.linear.com/product/LT3482
I did some Googling and found plenty of DC to DC inverters, but I'm
too busy (or lazy) to dig through the selection guides.


All I've looked at so far fell short, at around 48 volts. Probably
over 100 datasheets in that project folder. IIt's no big deal, as lomg
as I finish it before I die.


BTW, Jeff Angus is back on a few newsgroups, but he can't access this
group most of the time. He is posting as Fox's Mercantile.

Yeah, I know. Every time I screw up in this newsgroup, he sends me a
nasty email. Ocassionally, he agrees with me, which means I must have
really screwed up badly.


Watch out, or he send you under the workbench to think about what
you've done. Whatever you do, stay out of his stash of Corona & donuts
if he does. ;-)

On Fri, 15 Feb 2013 16:12:12 -0500, "Michael A. Terrell"
wrote:


I want a rechargeable battery pack
with built in DC-DC converters for the 90 V plate & 9 V filament
supplies.

Maybe...
http://www.maximintegrated.com/app-notes/index.mvp/id/1751
While the above example can only deliver 1ma, the basic idea should
scale nicely to something with more power.

More general and more interesting:
http://www.maximintegrated.com/app-notes/index.mvp/id/1109

I would be tempted to take a 12v to 117VAC cheapo inverter and modify
the output circuit to produce DC instead of AC. The feedback should
be adjustable so that the output can be set to 90VDC. The trick is
finding one that includes a schematic.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Thursday, February 14, 2013 8:29:13 AM UTC-7, wrote:

I have a Dell Optiplex SX260 small desktop type computer that won't
boot up. When I press the power button, there is no display on monitor, no
HDD spin up noise. The only "life" I see/hear is the power light comes on and
the fans run. I tried a bootable CD, but the CD drive doesn't "run".

I checked all the on board fuses (all good), solder joints, and power
supply output voltages with a load. The CMOS (RTC) battery is good.
I even removed and reinstalled the CPU.

Many Dell Pentium 4 motherboards contain bad Nichicon brand capacitors because Nichicon goofed up the production of models HM(M) and HN(M) from about 2002-2004. The date codes are in the form LYYMM, where L is a letter, YY = last 2 digits of the year, and MM = week of the year. So H0324 means the year 2003, week #24. 4-5 of those capacitors are 1500uF, 6.3V, 10mm diameter and located around the DIMM sockets and AGP socket. Behind the CPU are about ten 1800uF, 6.3V, 8mm caps and another 3-4 1800uF, 16V, 10mm caps on the other side of the MOSFET heatsink. Those may be Rubycon brand (big "K" stamped in the tops) model MBZ or MCZ instead of Nichicon (big "+" stamped into tops). The Rubycons were never defective, but TheCapKing.com says the Pentium4 was so power hungry that even those caps can go bad in 5 years. Most caps in motherboards can't be tested with an ESR meter except by unsoldering them because so many are in parallel.

Some people replace conventional wet electrolytic caps with dry solid polymer caps, which are more durable in heat. Here's some information about doing that:

http://www.badcaps.net/forum/showthr...ghlight=gx-270

BadCaps.net not only has a great deal of information but also sells high quality caps.

Be careful about counterfeit caps. DealExtreme has sold them, some being pretty obvious fakes (Teapo brans substituted from Sanyo or Nichicon), and apparently only one Ebay dealer sells only genuine caps:

http://stores.ebay.com/PC-MotherBoard-Capacitors-Store

Jeff Liebermann wrote:

On Fri, 15 Feb 2013 16:12:12 -0500, "Michael A. Terrell"
wrote:

I want a rechargeable battery pack
with built in DC-DC converters for the 90 V plate & 9 V filament
supplies.

Maybe...
http://www.maximintegrated.com/app-notes/index.mvp/id/1751
While the above example can only deliver 1ma, the basic idea should
scale nicely to something with more power.

More general and more interesting:
http://www.maximintegrated.com/app-notes/index.mvp/id/1109

I would be tempted to take a 12v to 117VAC cheapo inverter and modify
the output circuit to produce DC instead of AC.

That would require a lot of filtering to keep hum out of the audio
and harmonics out of the RF.

The feedback should
be adjustable so that the output can be set to 90VDC. The trick is
finding one that includes a schematic.


Where is the fun in that? it's more fun to start with a blank page.
;-)

I want to run at least 100 KHz, but would prefer a higher frequency.
The estimated average current is 10 mA from the datasheets for the
tubes. A torritdial transformer will raditae less noise, be more
efficient and the entorecirccuit should fit a deep drawn box the size
ioof an Altoiods box, or one of the hundred or so NOS bathtub caps with
bad seals I have in the shop. They are easy to open, with a propane or
aceteleyne torch. Melt the solder around the edge, and find the
soldered over vent hole. Shove a dental pic in, and pop it open. The
lazy way is to solder up a box out of scrap PC boards.