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Discussion Starter · #1 ·
My daughters computer would not power up. I went through a few trouble shooting procedures the last being.... With everything in the machine connected it would not power up at all. I disconnected everything but the MB 20 pin and tried again the fans all started and the green light on the PSU stayed on. I plugged in the HD and DVDD and it powered up as well. I then plugged in the P4 connector for the CPU and everything died again. Is the CPU fried......motherboard???

Thanks for any help,
Regards, Capp
 

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Discussion Starter · #3 ·
Re: Is the CPU fried

No, I won't be able to do that, however I metered the connector with it removed from the Mobo with the power on and I got 12 volts on both yellows. so it looks like the power supply is working, however there was no load. It looks now like a short in the Mobo. That is what I am going to attempt to replace.... Hope I don't find out it's the CPU.

Thanks for your help and I kindly encourage anyone else with any insight into thiis sort of problem to please chime in. I'd appreciate it.
 

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Discussion Starter · #4 ·
Re: Is the CPU fried

I tried another PSU, because it's quick and easy and had the same results plugging in the 4 pin plug to the MB for CPU power and everything immediately kicks off power wise. Anyone at all know of this sort of problem ??? I don't really want to swap out a MB and then find out it was the CPU... Any advice???..... Anyone???

Thanks
 

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Re: Is the CPU fried

Are you certain that you are using the +12 molex connector from the power supply instead of the extra 4 pin connector from the ATX power. They look similar and it will fit with either, but will not work when the extra 4 pin ATX plug is used.

I would suggest that you need to troubleshoot it with nothing but the 20 pin connector, the CPU and heatsink fan connected to the motherboard, plus the +12 molex connected to the motherboard....see what happens. MAKE SURE you are not using the extra 4 pin connector from the ATX connector for the molex plug. The molex that connects to the motherboard will come directly from the power supply and not be connected in any way to the 20 pin connector. The look very similar and both will fit the socket, but the ATX 4 pin will not power it up.
 

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Discussion Starter · #6 ·
Re: Is the CPU fried

I realize I said I had a 20 pin connector to the MB, but actually it is a 24 pin (with all in use), plus a separate 4 pin 12 volt CPU power supply connector which comes directly from the PSU also.( This is the one which when connected kicks the power off) Its pins are 2 x 2 in a square plug (2 black, 2 yellow) It was the first time this case has been opened and I made note of all the connections, which is not very difficult to keep track of. I have powered up with just the 24 pin connected and fans run and power stays on. Even when I plug in the HD ans DVD it still powers up. Everything works until I try to power up with the CPU 4 pin 12v power supply connector in place. It dies immediately (short somewhere I believe, just wondering if it's MB or CPU) as I've tried a new PSU already.

Thanks.
 

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Re: Is the CPU fried

My best guess would be motherboard. You have done a nice job of troubleshooting and have narrowed it down to the CPU and Motherboard. Those CPU's are actually made pretty darn well and we rarely see one that dies unless there has been some kind of line spike that takes them out. However, even when that happens, they normally won't power up at all if they are bad. Therefore, my call as the motherboard going South.
 

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Discussion Starter · #8 ·
Re: Is the CPU fried (solved)

Thanks for the help. Just replaced the MoBo yesterday and it solved the problem. It was a much easier process than I expected however I prepared well beforehand as I had never replaced one before.
 

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Yes great troubleshooting. Grats on a successful fix.
 
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