Bad mobo?

[wayneP]

This morning when I went to use my computer it was dead. I had used it last
evening and it was fine - left it on and went to bed. The machine has been
working fine for about a month and I haven't made any hardware changes since
I initially assembled the system.

I shut off the power to the computer and powered it back up. There were no
beeps, all the fans started briefly and then stopped. The power supply is a
400 watt generic unit. I tried another 250 watt Codegen ATX P4 power supply
just to power up the mobo. This power supply had been in service for years
on a socket 370 board and should be adequate to power up just the mobo. The
same thing. No beeps and the fans spin briefly and then stop. The only
things I did notice was that there seemed to be a large draw on the electric
circuit as I powered up with either power supply ( a light connected to the
same power strip dimmed as the power switch on the power supply was switched
on ). Also there is a LED lit on the mobo which has something to do with
the AGP card voltage. Supposedly, the mobo can only use 1.5 volt AGP cards.
If you try to use a 3 volt card, the LED will light up and the board won't
work. I've tried two different AGP cards on the mobo. One was a 4x ASUS and
the other is a MadDog 8x. Both are 1.5 volt cards, at least, the slot
configuration is consistent with 1.5 volt cards.

This is a SOYO i865 mobo with a Celeron D cpu with a ThermalTake fan, 2x256
Kingston 2700 sticks, a multimedia card and a couple case fans.
Does any one have any suggestions?

Wayne

 

[Adam S]

This is a SOYO i865 mobo with a Celeron D cpu with a ThermalTake fan,
2x256

Kingston 2700 sticks, a multimedia card and a couple case fans.
Does any one have any suggestions?

Have the capacitors blown?
http://www.pcstats.com/articleview.cfm?articleID=195

I have dealt with quite a few motherboards that have stopped suddenly,
nearly always it has been due to the blown capacitors.

It is possible to change them, but it can be tricky getting hold of the
proper capacitors. Also it can cost nearly the same as a new motherboard,
depending on how many you need to replace.

Adam S

 

[ToolPackinMama]

Have the capacitors blown?
http://www.pcstats.com/articleview.cfm?articleID=195

Thanks for this link. I am surprised by how common this problem has
become lately.

 

[Papa]

Thanks for this link. I am surprised by how common this problem has
become lately.

I seem to recall a news report some months ago about a sudden surge of poor
quality capacitors being installed on motherboards. Hope they have this
under control by now. Just did a Google search. I was right. Here is a copy
of a report found on the internet:

"Taiwanese component problems may cause mass recalls

Faulty capacitors may afflict mobos, modems

By Paul Hales: Tuesday 05 November 2002, 15:00

PROBLEMS DOGGING low-ESR aluminum capacitors produced in Taiwan could prompt
recalls of desktop PCs in North American and beyond, research suggests.

Taiwanese sources confirmed that as many as eleven manufacturers of low-ESR
aluminum capacitors in Taiwan might have been using a poor-quality
electrolyte in the capacitors. Reports first started to surface in September
among "brand-name" computer manufacturers that there were problems with
low-ESR aluminum capacitors produced in Taiwan.

These reports suggest a poor-quality, water-based electrolyte had been
supplied to multiple manufacturers of low-ESR aluminum electrolytic
capacitors in Taiwan.
The electrolyte, is a Taiwanese version of the Japanese P-50 water-based
type, but produced without the proper additives required to stave off excess
hydrogen gassing, according to Dennis Zogbi, owner of the Paumanok Group .
Zogbi, "aluminum capacitors produced with the P-50
knock-off tend to fail catastrophically, by blowing open the rubber seal and
leaking liquid electrolyte on the printed circuit board. These failures
reportedly occur at half the rated lifetime of the components."

It is not currently known how many market segments may have been affected by
these poor parts, which can be found in motherboards, switchmode power
supplies, modems and other PC boards.

The failures of the aluminum capacitors might just be the 'tip of the
iceberg,' says Zogbi. "Other component failures from low-cost Asian
suppliers might be forthcoming," he warns.

Around 30 per cent of the world's supply of aluminum capacitors is
manufactured in Taiwan, according to the Paumanok Group. Confusion over
which manufacturers may have used the faulty electrolyte is sending buyers
back to Japan to source their capacitors.

The extent of the problem in product that has already shipped won't become
clear until components start failing, which may not happen until halfway
through the products' lfe expectancy."

END OF QUOTE

 

[larry moe 'n curly]

This morning when I went to use my computer it was dead.
The machine has been working fine for about a month

There were no beeps, all the fans started briefly and then
stopped. The power supply is a 400 watt generic unit. I tried
another 250 watt Codegen ATX P4 power supply just to power up
the mobo. This power supply had been in service for years
on a socket 370 board and should be adequate to power up just
the mobo. The same thing.

This is a SOYO i865 mobo with a Celeron D cpu with a ThermalTake
fan, 2x256 Kingston 2700 sticks, a multimedia card

I had a really bad 250W PSU that would shut down in thirty seconds with
just a 1.3 GHz Duron, slow graphics card, and no drives connected.
OTOH another person had a high quality Fortron/Sparkle 250W PSU that
was able to run his faster CPU, fairly fast graphics card, a couple of
7200 RPM HDs, and at least one CD-RW. My guess that your Codegen is
lot more like my 250 generic than his 250W Fortron.

I don't know if your system has developed bad capacitors on the mobo or
inside the 400W PSU, but I have a 300W Antec only 1-2 years old where a
couple of capacitors swelled up, one just a week after the other
(capacitor ESR measured fine previously), although it still worked OK
with the light load it was running (500 MHz CPU, 1 CD-RW, 1 HD, about
60W).

 

[wayneC]

Thanx for the suggestions.

I've replaced the battery and that didn't help. I've taken the mobo out and
there isn't any obvious capacitor leaks or bulging and I haven't seen any
evidence of shorting, although this failed during the night and there may
have been some evidence of shorting but after 10-12 hours the smoke/smell
would have dissipated.

I did try to use the old 370 board and processor but that wouldn't work with
the generic 400 watt power supply either. However, it won't work with the
original 250 watt power supply either after powering up with the 400 watt
PSU. I tried this 250 watt supply on the
P4 Soyo board and it powered up the fans initially, but when I hooked
everything back up I was back to the original position. No beeps, no fans
and the LED on the mobo was lit.

If there is something shorted on the mobo could that have blown the 250 watt
Codegen PSU from the 370 system?

Wayne

 

[larry moe 'n curly]

I've replaced the battery and that didn't help. I've taken
the mobo out and there isn't any obvious capacitor leaks
or bulging and I haven't seen any evidence of shorting,
although this failed during the night and there may have
been some evidence of shorting but after 10-12 hours the
smoke/smell would have dissipated.

I did try to use the old 370 board and processor but that
wouldn't work with the generic 400 watt power supply either.
However, it won't work with the original 250 watt power
supply either after powering up with the 400 watt PSU. I
tried this 250 watt supply on the P4 Soyo board and it
powered up the fans initially, but when I hooked everything
back up I was back to the original position. No beeps, no
fans and the LED on the mobo was lit.

If there is something shorted on the mobo could that have
blown the 250 watt Codegen PSU from the 370 system?

Any good PSU won't be damaged by a short, but my own not-so-good 250W
(not Codegen), despite containing protection circuitry meant to prevent
such damage, blew an MOSFET anyway when its +3.3V rail was shorted by a
DIMM plugged in backwards. I've also had some PSUs blow their high
voltage transistors when they were shorted and their fuses blew,
including an old Enermax.

Are you saying that when you inspected the mobo, you didn't see any
places where copper traces ran close enough to the holes that a screw
or brass standoff _could_ have touched them? Or that the mobo could
have touched the mobo tray if flexed?

If a chip wasn't damaged, then it's likely that the mobo can be
salvaged by changing a few bad capacitors, MOSFETs, or diodes. The
latter two can be tested with just a multimeter, but bad capacitors
often seem OK when checked with a multimeter.

 

[wayneC]

larry moe 'n curly,

I didn't see anything out of the ordinary when I inspected the board. The
fact of the matter is that the machine had been running flawlessly except
for an LED on the board that seemed to indicate that the AGP card was
running at the wrong voltage (3.3 instead of 1.5). However, I tried two
different AGP cards, one a 4x card and the other an 8x card and the LED
remained on; so I just ignored it. After adding the 8x board there was what
sounded like an alarm at boot as the AGP info appeared on the monitor. There
was nothing anywhere about this alarm and I it wasn't there using the 4x
card. A note to SOYO tech support was never answered.

The machine was operating fine and was left on most of the time for the
month or so since assembly. After finishing some work one evening and
leaving the machine on, when I went to use it the next morning it was dead
except the LED on the mobo was still lit.

Wayne