Question Failure of capacitors near the cpu

[X16]

Ive got an old Asrock agp8x p4i65g motherboard that has 4 16v 1200uf bulged capacitors near the cpu.When powered on the psu and cpu fan spins for less than a second and shuts off. What is the purpose of those capacitors? After replacing them all with new ones the issue still persists.Please help.

 

[Lutfij]

Welcome to the forums, newcomer!

What is the purpose of those capacitors?

Delivery of power to the CPU.

 

[X16]

Welcome to the forums, newcomer!

What is the purpose of those capacitors?

Delivery of power to the CPU.

I replaced all of them but still can't get it to boot. It stills powers on for a second, then back off.

 

[bill001g]

So how did you determine those were bad. There are lots more capacitors on the motherboard how do you know those are good or bad.

There are lots of small little parts you can barely see that can cause a whole motherboard to fail.

Fixing electronics is almost impossible even if you were to have the correct tools. Way to many little parts with no documentation on what they are being used for.

 

[Lutfij]

There are other componentry besides capacitors if you pay close attention to the area around the CPU's socket. So to double down, how did you verify that the issue was with the capacitors(outside of the visible bulging)?

 

[X16]

So how did you determine those were bad. There are lots more capacitors on the motherboard how do you know those are good or bad.

There are lots of small little parts you can barely see that can cause a whole motherboard to fail.

Fixing electronics is almost impossible even if you were to have the correct tools. Way to many little parts with no documentation on what they are being used for.

Yes, it was obvious they were done for as they had bulged and exploded.

 

[X16]

There are other componentry besides capacitors if you pay close attention to the area around the CPU's socket. So to double down, how did you verify that the issue was with the capacitors(outside of the visible bulging)?

After desoldering i tested them and they show far lower capacitance than they're rated for.

 

[DSzymborski]

The problem here is that it appears you assumed the capacitors bulging was the cause of your problems rather than something caused by the problem, such as power source. There are lots of things that can go wrong on a motherboard, but at this point, I can't imagine the time, effort, and money are worth repairing a 20-year-old motherboard.

 

[bill001g]

Your problem is a capacitor or other part can be bad and still look fine. How do you know which part to try to unsolder and test next.

 

[X16]

The problem here is that it appears you assumed the capacitors bulging was the cause of your problems rather than something caused by the problem, such as power source. There are lots of things that can go wrong on a motherboard, but at this point, I can't imagine the time, effort, and money are worth repairing a 20-year-old motherboard.

Well, im doing this just for fun so no regrets on the time effort and money,anyway must not be the power source since I've tried another psu which was confirmed working on another board.

 

[drea.drechsler]

Well, im doing this just for fun so no regrets on the time effort and money,anyway must not be the power source since I've tried another psu which was confirmed working on another board.

A likely defective part will be one or more of the FET's, there are 6 total from what I can see. Another likely defect could be a fuse or fused link, although you'd be so lucky for it to be. A much more difficult defect to find would be one or more resistors that have shifted values (common with age) throwing off operation of the whole VRM circuit.

Or simply...the CPU is now toasted too. I tend to think this is most likely since failing caps could easily have let very high voltage spikes (+12V or less of course) reach the CPU.

 

[DSzymborski]

Well, im doing this just for fun so no regrets on the time effort and money,anyway must not be the power source since I've tried another psu which was confirmed working on another board.

No, I mean a junky power source could have caused the problems. That probably isn't fixed by swapping out for another one.

 

[X16]

A likely defective part will be one or more of the FET's, there are 6 total from what I can see. Another likely defect could be a fuse or fused link, although you'd be so lucky for it to be. A much more difficult defect to find would be one or more resistors that have shifted values (common with age) throwing off operation of the whole VRM circuit.

Or simply...the CPU is now toasted too. I tend to think this is most likely since failing caps could easily have let very high voltage spikes (+12V or less of course) reach the CPU.

Could indeed be 2 of the FETs near the ATX 12v, yeah not gonna try to replace them. 😂 thanks btw!