unnecesary recapping

[JorgeHernan]

I have an Asus p4sp-mx which i thought that bad capacitors were causing problems.The original ones were 1200 uf x 16 volt so i changed them all but didn't find 1200uf x 16volt in the stores so i put 1500uf x 16.The problem this motherboard had was that it didnt post fans spinning everything fine but it did't post.that's why i thought that the capacitors were causing the problem in the first place.It turned out that the problem were the P4 1.7 socket 478 which i used to test the motherboard.This processor was fried prior to carry on the motherboard testing.It has tiny tiny bubbles in the pin side between the smd decoupling capacitors.My question is :can this increase in capacitance (originals 1200uf x 16v replaced by 1500 x 16v) kill a good working cpu ? Thanks

[kc8adu]

Re: unnecesary recapping

no.
but the vcore vrm can if there are any shorted mosfets.
+12 to the core=smoke.

[JorgeHernan]

Re: unnecesary recapping

Thank you i am asking because i am about to run this motherboard using a good working celeron 2.8 so i want to be sure the cpu will be free of any kind of harm because of this increse in capacitance.Thank you.I 'll tell you later about the results of this motherboard/cpu test

[willawake]

Re: unnecesary recapping

if you read again
he is saying this board may kill your good working celeron 2.8
check vcore before you proceed

[Per Hansson]

Re: unnecesary recapping

You need to start the board without a CPU and measure the pins which supply VCC to the CPU to make sure they are within tolerance

Just measuring on the outputs of the Mosfets or Coils is enough

[JorgeHernan]

Re: unnecesary recapping

Sorry about my ignorance on electronics but what is the output of a mosfet ?Source, Drain or Gate?Thank you

[gg1978]

Re: unnecesary recapping

you have to have a cpu in the board to get Vcore.. If you boot with no CPU, the VRM will not turn on. There's a few pins on the cpu that are either open or shorted to ground that form a code called the VID that tells the VRM what voltage the CPU needs..

[gdement]

Re: unnecesary recapping

If you put a positive probe on the drain (tab on the back of the mosfet) and the negative on some ground, such as the side of the PSU, then you should read what voltage is being applied to that circuit.

The mosfets in question would be somewhere near the CPU, but you may have to try a few of them to get the right ones. As gg1978 said, the Vcore circuit will read 0V if there's no CPU. I'd try checking for that at least - if you find something like 12V then you know something's probably wrong.

If you do find the 0V you expect, then I'm not sure what to do next unless you have a CPU you're willing to sacrifice. Maybe the dead one can still be used to check voltage with.

I don't think CPUs die very often on their own, so I'd be very concerned that this board is a CPU killer.