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HP Recommended

I have an HP Pavilion all in one model 22. All of a sudden, it won't boot. I unplugged everything and have it taken apart where I can see the motherboard. When plugged in, here's no noise or fan spinning and I do see a small light near where the power cord plugs in

 

. I have it facing me with the power button in front on my left and the disk drive in the back. I unplugged the ribbon cable from the power button and was told I could short out pin 2 and 4 to bypass the power button. It didn't work.  Pin 1 is to my left.

 

I followed the ribbon cable to the motherboard and was told I could use a flat head screwdriver to short out the pins going into the mother board. I'm afraid to try that since I wonder what pins 1 and 3 are for. A flat head screwdriver would connect all 4 pins.

 

If pin 1 and 3 are dummy pins then that's ok. If it still won't come on after shorting out those pins on the motherboard I assume it 's a bad power supply. Any suggestions would be welcome.

5 REPLIES 5
HP Recommended

I understand your reluctance to short out pins at random -- as picking the wrong ones will fry your motherboard.

 

Reading what you have said, I agree that the most likely culprit is the PSU -- but you need to know that HP uses custom PSU, not retail ones.  So even though the retails ones are a standard form factor and will fit in the case to replace the HP one, it still might not work with your motherboard.

 

There are PSU testing tools out there that you can look for which will enable you to test the PSU leads to see if that is the issue.  That might be a better bet than just buying a new PSU.  I have replaced countless PSUs in the systems I support and that tool has come in handy.  I got it from MicroCenter -- so you could check online to see if they still carry it.



I am a volunteer and I do not work for, nor represent, HP
HP Recommended

Since you work on these computers, how can I find out how to start the computer bypassing the start button, since it could be that is the problem. Read my post again and see if you can answer that question - thanks

 

Also Micro Center doesn't have the HP power supply. I'm having trouble finding one. It seems HP doesn't even sell parts

HP Recommended

You have to short out the power leads -- but all the PCs I work on were custom built (by me), so I have the motherboard manuals showing the pinouts; thus, I don't risk shorting the wrong pins.

 

HP does not sell their PSUs but if you can get the part number from yours, you might be able to find one online.

 

I would still go with the PSU testing tool first -- even though it is likely the PSU is the issue.



I am a volunteer and I do not work for, nor represent, HP
HP Recommended

I replaced the power supply and made sure it was a TPC-LA57. It didn't work. I also put in a different HD with an image file of the HP from a a few months back. Still nothing. It's original HD, I tested it, and it was listed as "Caution" by Crystal Info, so it looks like it's failing. Yet I Was able to copy important files off of it.

 

Unless anyone thinks differently, It looks like the motherboard has gone out. Unless HP does something unusual to their computers that I need to know about. I've had many computers but all were custom made nothing like HP or Dell

HP Recommended

I understand ... which is why I never buy an OEM PC -- it's not possible to get the detail information needed to maintain it and all too often, the parts are custom and not available.



I am a volunteer and I do not work for, nor represent, HP
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