please help with LA-D451P Board repair

[roxboy1984]

Hi,

I know this is probably going to be a very noob question but i have this board that someone has worked on already and im trying to troubleshoot. the previous person soldered wires at "pci1026" for voltage injection and if I inject 2.5V @ 2Amp the CPU gets very hot. does this mean the CPU is likely fried? also it looks like multiple components have been removed from the area where the wires are soldered? any help is massively appreciated.

[mon2]

2v5 onto a CPU rail is far too high. CPU is likely dead now for sure. The injection voltage should always be kept at the lowest possible level which for us is often 0v8. Low voltage + highest current available on your power supply is ample to hunt down short parts.

[roxboy1984]

2v5 onto a CPU rail is far too high. CPU is likely dead now for sure. The injection voltage should always be kept at the lowest possible level which for us is often 0v8. Low voltage + highest current available on your power supply is ample to hunt down short parts.

Thanks so much for the reply. So where i injected is that on the CPU rail. is there any way i can check if i fried it.

[mon2]

In general, any component that is high speed, will operate at a low voltage. This allows for high frequency of high / low cycles since the voltage rise is smaller. CPUs are the same. At 2v5, that is very much beyond the voltage range of the device.

You can, remove all power. Measure the resistance to ground of the same point of the voltage injection. If the resistance is super low, the CPU is for sure dead.

[roxboy1984]

In general, any component that is high speed, will operate at a low voltage. This allows for high frequency of high / low cycles since the voltage rise is smaller. CPUs are the same. At 2v5, that is very much beyond the voltage range of the device.

You can, remove all power. Measure the resistance to ground of the same point of the voltage injection. If the resistance is super low, the CPU is for sure dead.

Thanks, so i measured from Red wire to ground and im getting 5.3 ohms. would you say thats dead?

[mon2]

No, does not sound like this is a dead cpu but wait on other comments. The key concern is the very high voltage used for injection onto the CPU rail. It is possible that the PCH which is a part of the large CPU package is defective from this injection.

[roxboy1984]

No, does not sound like this is a dead cpu but wait on other comments. The key concern is the very high voltage used for injection onto the CPU rail. It is possible that the PCH which is a part of the large CPU package is defective from this injection.

Thanks, as always your help is much appreciated. So there is no other way of testing to see if things are still ok and the problem lies elsewhere?