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Dead Motherboard?

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Oct 7, 2007
6,597
US
Just want to make sure I'm not missing any tricks here. I think the motherboard is dead on desktop.
When you press the power button only the cpu fan and case fan run. Nothing else happens - like no video.
Tried pulling all the memory - no beep
Tried a second power supply - no difference
Pulled motherboard out of case - no difference

"Living tomorrow is everyone's sorrow.
Modern man's daydreams have turned into nightmares.
 
Probably the 5v (and lower) regulators on the board have 'gone'. Fans and drives run off the 12v rails.

Chris.

Indifference will be the downfall of mankind, but who cares?
Time flies like an arrow, however, fruit flies like a banana.

Never mind this jesus character, stars had to die for me to live.
 
Drives can run off the 12v rail, but most of todays drives, especially SSD and 2.5" drives run off just the 5v rails. I have a western digital blue that has both 5v and 12v ratings. I have a seagate and a crucial SSD both have just 5v.
 
Looks like some of the capacitors have "plumped" at the top - like a dome effect instead of being like a "crater" like most of them. No leakage but a different shape. Mobo was from 2010 - not sure if that was the era of the "bad caps wave of misery" period.

Interesting also that the motherboard won't turn on or off by the switch or shorting the pins. It just turns on when you plug in the power. I have written it off and moved on for this customer.

"Living tomorrow is everyone's sorrow.
Modern man's daydreams have turned into nightmares.
 
Drives can run off the 12v rail, but most of todays drives, especially SSD and 2.5" drives run off just the 5v rails.

I'll clarify.
... ... drives with motors run off the 12v rails.

Chris.

Indifference will be the downfall of mankind, but who cares?
Time flies like an arrow, however, fruit flies like a banana.

Never mind this jesus character, stars had to die for me to live.
 
no, some motors , The seagate drive is mechanical, it still only has a 5v rating. it is a momentus 7200.4
 
Did you consider replacing the capacitors? Realize that you have moved on but a cap job was a possible fix.

Ed Fair
Give the wrong symptoms, get the wrong solutions.
 
Replace capacitors?? I am not that competent at soldering. Would probably catch board on fire!!! I know my limitations. We can buy a motherboard for $58 if there was a need to resuscitate the old computer. We have a brand new I7 / 16GB machine with an SSD now that can work harder than my customer can.

I guess I wouldn't even know WHO would do such a thing around here. Micro Center?? Or would you trust some mom & pop computer store?

"Living tomorrow is everyone's sorrow.
Modern man's daydreams have turned into nightmares.
 
By the time you end up paying a tech to figure out what happened and physically repair the motherboard you have spent more then a new one would cost. So why not just get a new board. The only time doing a repair is cost effective is if you are doing the repair yourself .

Bill
Lead Application Developer
New York State, USA
 
And if you're good at it AND if you don't sneeze while doing the repair, right? I'm not about to mess with capacitors on modern motherboards, even though I know it is done by others.

"But thanks be to God, which giveth us the victory through our Lord Jesus Christ." 1 Corinthians 15:57
 
My skills have deteriorated over the years from lack of use but probably would try if there was any difficulty in getting a replacement. I still do component replacement on less complicated double sided boards.

Ed Fair
Give the wrong symptoms, get the wrong solutions.
 
I've done it, but with the multi layer boards and large ground planes, it is really hard to get the old caps off, unless you use something like chip quick and other alloys that keep the solder liquid at a lower temperature, otherwise it is real easy to lift a trace.
 
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