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Mini-ITX system won't even POST

Last response: in Components
June 13, 2010 4:16:57 AM

Don't know if this is a power supply issue or mobo, but am suspecting power.

System: mini-itx 2699 system from LogicSupply, EPIA M10000 mobo, about 4 yrs old, Morex2699 case, external power brick with internal 80W DC/DC converter. System has run almost 4 years solid, rebooting only for updates.

Problem: For a number of months it was not holding bios info, rebooting badly, and, finally, now does not boot at all. CPU fan does run, but no HD light, and case fans don't spin.

Discoveries/attempted solutions: When opened up, data ribbon cable to HD was frayed, lots of copper exposed.
I traded that cable out for a new (sealed plastic bag) cable; no diff.
Replaced CMOS battery (battery tested - good). No change. No beeps, no video, no HD front panel light, and HD does not spin (no vibration felt).
Reset CMOS per instructions (pwr off, change jumper, change it back). Even disconnected HD and CD drives.

No change. CPU fan and power light on, no beeps, no video.

Am suspecting partially failed DC-DC converter board. Is there anything else I can try, without a voltmeter to actually test output of DC/DC conv. board? CPU fan spins, front panel light goes on, otherwise no sign of life.

Will see if CPU fan and case fan voltages are the same, and connections, if they are, just to see if case fans are toast, but I don't want to replace working parts if I can help it.
I don't have a spare ATX PSU, so I can't plug that into the mobo.

Any ideas?

Thanks in advance -

More about : mini itx system post

Best solution

a b ) Power supply
June 13, 2010 4:58:57 PM

Big possibility that your PSU is dying.
Well, i guess the only way to make sure is to try different PSU.
It's a very dangerous to use a dying PSU, it could frying everything inside your case...
June 13, 2010 8:03:14 PM

Thanks - will see if there's anything I can scrounge up. I hate paying $80 for a full power kit if only the PSU, or only the DC/DC converter, is dead, but I don't know which. Perhaps I can pull an ATX PSU from aged machine at work and run it straight to the mobo, bypassing dc/dc converter. At least I could see then if the mobo is toast. But I still wouldn't know if PSU or dc/dc is bad, or both.
Computer repair or home repair, it always takes more trips to the store than you first think...
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a b ) Power supply
June 14, 2010 3:14:29 AM

i am quite sure its ur psu. i had 2 mini itx systems that ran with external bricks and the little dc boards in the computer go bad... cheap crap is the biggest reason
June 14, 2010 6:45:29 AM

shovenose said:
i am quite sure its ur psu. i had 2 mini itx systems that ran with external bricks and the little dc boards in the computer go bad... cheap crap is the biggest reason

Did you have to replace both brick and board?
I guess I can't complain too much - damned thing's been running 4 years solid day and night...
a b ) Power supply
June 14, 2010 2:46:42 PM

I didnt replace either...i tries to jam a microatx psu in :) 
but it was the convertrr becuz no matter how many adapters i tried it wouldnt work. The fNs would go on but the pc wodnt work
June 23, 2010 1:30:13 PM

Replaced DC/DC converter board (internal) and case fans (stuck), and all is well. External brick was fine. I'm back in business.
June 23, 2010 1:30:59 PM

Best answer selected by glennho.