Motherboard not turning on.

[KHURRAM]

I have Intel D845GRG motherboard with intel celeron 1.8 Ghz processor.

The board is not turning on except stand by light and green power light on casing.

I have also tried change the PSU but nothing worked.

Only way to run it is to short green and black wires on main power connecter on board. I have not got any problem in this way of running it and found no over heating every thing runs properly and cpu tempreture goes to 58 degree celcius.



The "stand by" light is on, and voltages are under 3% limit.

I have also tried to start it by removing all wire from front panel connector and then shorting the power on leds of front panel connector, but nothing happened.

12v and main power connectors are connected rightly.

Also I have two slightly swollen capacitors along side processor socket 6.3v 3300uF.

Also the one of set of green wires at back of board have very small screw driver scratch.

[Gordon01]

Re: Motherboard not turning on.

Does the board start up correctly and runs OS or just starting fans when you short green and black?

[ratdude747]

Re: Motherboard not turning on.

I see the problem. it just spins the fans I bet. I think i know wht:

you need to recap your board.

do not replace (unless obviously bad or broken)

any polymer caps (usually near the CPU, no vents, rounded edges, no sleeve)
rubycon
nichicon*
any chemicon brand** (shield logo)
panasonic (T shaped vent, m logo on sleeve)


*- replace any HM or HN, with a datecode of 01-04, and 05 if any of that code are bad. the datecode reads Hyyww or Ayyww, where yy= the year (what we want) and ww the week (doesn't matter)

*- replace any KZJ or KGZ

anything else needs to go... not all caps bloat and/or leak when they fail.

[KHURRAM]

Re: Motherboard not turning on.

Does the board start up correctly and runs OS or just starting fans when you short green and black?

Yes after shorting, everything works well and excellently including OS and everything.

[KHURRAM]

Re: Motherboard not turning on.

I see the problem. it just spins the fans I bet. I think i know wht:

you need to recap your board.

do not replace (unless obviously bad or broken)

any polymer caps (usually near the CPU, no vents, rounded edges, no sleeve)
rubycon
nichicon*
any chemicon brand** (shield logo)
panasonic (T shaped vent, m logo on sleeve)


*- replace any HM or HN, with a datecode of 01-04, and 05 if any of that code are bad. the datecode reads Hyyww or Ayyww, where yy= the year (what we want) and ww the week (doesn't matter)

*- replace any KZJ or KGZ

anything else needs to go... not all caps bloat and/or leak when they fail.

Can you please explain simply. Nichicon HM(M) H0250 105degree
(swollen) and KZE (M)105degree, 2(9), DZ, around cpu.

[berniedd]

Re: Motherboard not turning on.

If everything runs fine after you've shorted the green and black wires together .... the power switch itself becomes suspect. Had one such desktop come in a week ago, my solution was to use the reset switch as the power on switch. Didn't want to dig into it, so I just switched the wires from the power to the reset switch. And told the owner that if he needed to do a hardware reset, just pull the power plug, wait 10 seconds, reinsert it and press the reset (which is now the power) switch.

[KHURRAM]

Re: Motherboard not turning on.

I have also tried that by shorting the power pins of front panel connector of the board.

[KHURRAM]

Re: Motherboard not turning on.

What to do now?

[PCBONEZ]

Re: Motherboard not turning on.

Inspect chipset and MOSFETs for any cracks, pits, or shiny spots that indicate melting or arcing inside.

If you see none then:
*- replace any HM or HN, with a datecode of 01-04.
*- replace any KZJ or KGZ.
*- replace any 85C caps.
That's what goes bad on Intel boards that age.
.

[PCBONEZ]

Re: Motherboard not turning on.

Also I have two slightly swollen capacitors along side processor socket 6.3v 3300uF.

That was your clue.
.

[b700029]

Re: Motherboard not turning on.

Check 5VSB and voltage across power switch pins.

[Gordon01]

Re: Motherboard not turning on.

Please check the battery voltage(with and without PSU) level and simple logic(74xx) around front panel connector.
Then: replace 32768 quartz, of no result - replace SuperIO

[ratdude747]

Re: Motherboard not turning on.

recap it first, and then see what happens. bad caps are never a good thing... a bloated cap is always a bad cap and the symptoms match the usual bad caps symptoms (no POST, spins fans only)