Will not power up

[subseageorge]

After a lightning storm my computer will not start. When i press the start button the blue led is on. Only while i hold the power button in.  Goes off when released.  No fan nothing.  Any suggestions ??

I have surge protection and UPS on power supply and they are fine.

Thanks

George

[old_geekster]

@subseageorge , welcome back to the forum.

The first component that I suspect when this happens is the power supply unit (PSU).  It is the only source of power for the computer.  If the slightest surge in power got to it, it can fail.  If it is working properly, then, test the processor and memory.  Next, check all of the capacitors to assure none of them are bulging.

[subseageorge]

Whilst checking some simple things, I found that the PSU starts and the fan runs when it is disconnected from the mother board. 

But when plugged in there is nothing. 

Does that point you in any specific direction ?

Thanks 

George 

[old_geekster]

You are welcome, @subseageorge!

There is still a possibility that the PSU has failed.  It may run when disconnected, but not have enough power to run the computer.  You should either test it or have it tested with the proper testing equipment to make certain.  Also, you should check the capacitors on the motherboard to see if any of them are bulging.  Here is an example:

Testing the memory and processor would be your next steps.

[subseageorge]

Thanks mate, i will try that , 

[old_geekster]

You are welcome, @subseageorge!

I would appreciate hearing the outcome.

[subseageorge]

I have had a look at the Capasitor caps and none looked bulged.  I have a spare PSU but,,  it does not have a 20 pin connector like my HP. Is there any way i can test the PSU with a multi meter ?  

And of course i will let you know the outcome 

Cheers 

[wb2001]

@subseageorge,

You can plug the ATX20 PSU into ATX24 motherboard

[subseageorge]

I do not have a spare motherboard to try it on, 

Would you by any chance have a map of the pins on the PSU connector with expected results if i use a muiti meter ?

Thanks 

[old_geekster]

You are welcome, @subseageorge!

Here is how it states to test the PSU in the Maintenance and Service Guide for the workstation:

To test the power supply:

1.Remove the power supply from the computer.

2.Connect the power cord to the wall outlet.

3.Connect power cord to the power supply.

4.If the power supply fans turn on and the built-in self-test (BIST) light illuminates, the power supply is good and the power supply does not need to be replaced.

Here is the Maintenance and Service Guide:  http://h10032.www1.hp.com/ctg/Manual/c06134496

I searched the Internet and HP website for the pin map for the PSU and couldn't find anything.  I believe that it will be standard, but can't be certain.  I believe you may find the specifications on the PSU itself.