Need help about motherboard fixing

[remzy]

Hello everyone! I've came here to seek for wisdom of more experienced people. The problem I have with my motherboard ASUS 5pg41-m lx is that there is a short somewhere and for the love of God i can't find it. There is one specific mosfet that burst every time when I replace it. There are 8 of them around the CPU and it's always the same one, the other ones always survive. I thought that my CPU was shorted at first, but after changing 3 CPU-s, the problem is still the same. I did found one shorted capacitor but that was it. Has anyone maybe came across the problem like this or had similiar experience. I would like to hear your opinion on this matter. Here are some pictures. There is flux on the board from resoldering mosfets on the motherboard. The circled mosfet is the problematic one. Also the two wires coming form the motherboard are connected to a capacitor, it couldn't fit between the coils so I just put it little above(that was the shorted one).

[cpt.charlie]

Re: Need help about motherboard fixing

Maybe your VRM conrolller is damaged (or mosfet driver if it uses) and keeps the mosfet high all time, some boards can boot even with one phase removed (use low power CPU in this case), i would remove the mosfets of the problematic phase and check if it boots.

You can also check the gate with a DSO and compare with other phases.

[remzy]

Re: Need help about motherboard fixing

I think that I found the problem. The component in question is epu asp0905b. I was touching the components while the mobo is connected to a psu and this component gets really hot. It's probbably in short circuit. I've orderd a new one from aliexpress. It was really hard to find.

I tried it withouth one "phase" and it still doesn't boot.

[jazzie366]

Re: Need help about motherboard fixing

I think that I found the problem. The component in question is epu asp0905b. I was touching the components while the mobo is connected to a psu and this component gets really hot. It's probbably in short circuit. I've orderd a new one from aliexpress. It was really hard to find.

I tried it withouth one "phase" and it still doesn't boot.

Can't find out what that thing is, but it looks like it could be a microcontroller.

If it is, replacing it won't help, as the new one needs to be programmed.

If it's not (which it might not be) then replace it and you should be fine.

[cpt.charlie]

Re: Need help about motherboard fixing

Can't find out what that thing is, but it looks like it could be a microcontroller.

If it is, replacing it won't help, as the new one needs to be programmed.

If it's not (which it might not be) then replace it and you should be fine.

It's the VRM controller, i think it's just a rebranded controller.