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HP Recommended

Hi,  my z420 will not power up. I have tried everything proposed. unconected everything, cleared bios panic bios update procedure. nothing works. blue light on motherboard, acouple of blink in the cdrom then dead after some sec it tries again and again. when all ram out there is a read light at the mainboard and one beep. Either the PSU or the motherborad is dead. Question. Is there a way to test the PSU decoupled from the mainboard?

1 ACCEPTED SOLUTION

Accepted Solutions
HP Recommended

your question is covered in the service manual for your model, and using google will/would also have answered your question

 

reguarding the "BIST" self test feature

 

playing with the bios recovery jumper (or any jumper on the board) is a good way to corupt a working bios, so a word of advice,... don't play with settings you don't understand

 

your z420 BIST test is the same as for the z820

 

remove all  power connections from the supply, (and all means all!!) from motherboard to Hard drives, optical drives and so forth,  then connect power cord to pwr supply. fan on supply should sping and led light just behing perforated grill should light.  if either fails, supply is defective if both work supply is working

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4 REPLIES 4
HP Recommended

you are not being clear, how many times does the bluse light blink? is it blink in in a repeating pattern?

 

did you try the bios recovery steps that "SDH" has previously posted here (use the forum search feature)

HP Recommended

Hi,

first thanks for your interest.

 

Sorry to hear i was not clear. I actually tryed to ask if ther is a way to exclude the PSU as the trouble maker.

I did read that the Z820 PSU had some kind of self test and wondered if my 600w PSU had the same.

 

Regarding the MOBO.

It's just 1 blink for a couple of seconds (no beep)

fans spins up (no high RPM just start)

Then system goes down

After some 4-5 sec it try to start again.

This hapens even if I remove all but power cables connected to the MOBO

Also same without graphic card.

Only time with change is when removing all ram.

Then there is blue light then red light and a beep

then same thing goes down.

Today I removed the CPU also.

blu light red light 3 beeps then turned down.

 

Regarding BIOS, I have tried both the panic jumber and the win B

same result.

 

Seemes the boot sequence never reach teh bios part.

PS! English is not my native language.

thanks again.

 

HP Recommended

your question is covered in the service manual for your model, and using google will/would also have answered your question

 

reguarding the "BIST" self test feature

 

playing with the bios recovery jumper (or any jumper on the board) is a good way to corupt a working bios, so a word of advice,... don't play with settings you don't understand

 

your z420 BIST test is the same as for the z820

 

remove all  power connections from the supply, (and all means all!!) from motherboard to Hard drives, optical drives and so forth,  then connect power cord to pwr supply. fan on supply should sping and led light just behing perforated grill should light.  if either fails, supply is defective if both work supply is working

HP Recommended

Hi thanks again.

 

Test performed.

 

No light no rpm. dead PSU.

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