Need Some Serious Help Diagnosing Optiplex 9020 SFF

[HaffaWaffle]

Hey Guys, I have a customer computer that was brought to me that is giving me some trouble And this may be a LOT of info.

 

Its a DELL Optiplex 9020 SFF. Customer brought it to me stating that they were doing some work in their shed (Which is powered by a cable connected to the house) and they hit a nail in the wood and hit the power line in the shed. The wife said she heard a "pop" in the office and when she walked in, their computer was off and would not turn back on.

 

I get the computer and sure enough, It will not power on... No diagnostic lights/beeps at all. So just to be safe, I replace his power supply even though the current one tests good. Still no power.

 

I remove all accessories, drives and RAM but one known good stick. Still no power.

 

Since the boards for these computers are really cheap, I decided I would order one just to see. The replacement motherboard arrives and I transfer over the RAM, CPU, power button cable and plug in the power supply. It actually POSTS! So after hooking everything back up and powering it on, the computer boots into windows and everything is running great. I run a stress test on the CPU just to make sure temps are consistent. Everything is running perfect. So the customer picks up the computer and is using it all day the next day and night. Then I get a text saying the computer shutoff while the customer was using it and now it won't power back on.

 

I get the computer back and sure enough its back doing the exact same thing it was doing initially. No power.... So I test the power cord the customer was using and there are no shorts in the cable, No blown caps or any signs of damage on the motherboard. I unhook everything but the bare necessities and drain the board of any power and plug it back in. No here is where it gets odd, Once I plugged it back in and pressed the power button the computer started to power on but then I heard a small POP and I immediately shut it down and unplugged it. But now each time I plug in the PSU, the system fans run at 100% and the PSU test light is on and green without me pressing the test button.

 

Can ANYONE assist me in figuring this out? I starting to believe that the customers house may have a short somewhere and its pushing too much voltage through the PSU and burning up the boards. But that's me just reaching for a solution where I can't find one.

 

PLEASE HELP!

[Protec]

When the cable was damaged by the nail, live voltage may have gone through earth and/or neutral which must have damaged something. The fan running at full speed could be anything really. The old Dells from years ago would do that if the CPU wasn't seated properly and I believe they do it if the RAM is bad. I can imagine the components were damaged by the event and it's probably best to just replace it, I certainly wouldn't trust it to be reliable again.

 

RAM can cause temperamental issues such as those you describe. I have a computer in the shed and the RAM in the computer failed not long ago. It started off just being unstable and sometimes freezing with the odd blue screen. Eventually, it failed completely and the computer couldn't turn on at all! With the RAM removed it is fine.

[HaffaWaffle]

I figured if the RAM was bad that there would be some sort of diagnostic lights or beeps. But I get nothing from either board now. And if the CPU was faulty, it wouldn't have booted up with the new board and ran perfect for almost 2 full days without shutting off.

 

I have ordered another motherboard with the exact P/N and rev version, A new USB hub just in case the old one had some damage to it, A new power button just to rule that out & an Intel Pentium G3220 LGA1150 CPU just for testing purposes. So we will see I guess.

 

I am wondering if they damaged the houses outlet or breaker box somehow when they hit that cable with the nail and caused a short somewhere.

[Protec]

I have a feeling that replacing the power button and USB hub would be rather fruitless. With a new CPU, motherboard and RAM, it should be fine considering most of the computer has been replaced at that point!

[HaffaWaffle]

Yea, I'm only replacing them because they were cheaper than dirt and I'm now repairing the computer under warranty so I wanted to rule anything I could out.