HP z620 worstation problem: red light + bip on startup

[invisio]

Hi!. I hope I will be clear because I'm dont speak very well english.

Since yesterday, my HP z620 worstation (2X xeon e5-2680; 96 gb ram, gtx1060) have a problem:

It doesnt boot.The Diagnostic LED blinks red 4 times and the system beeps 4 times.

Apparently it seems to indicate a power failure (as seen on https://support.hp.com/lv-en/document/c03599666).

I tryed to disconnect every thing (GC, HDD, fans..) but it doesnt fix it.

If I disconnect the power supply, this one accept to power on (fan on and green led on). --> it seems to be ok.

If I disconnect the second CPU board (aka riser), it boot! -> the problem comes from here.

If I connect the second cpu board, but disconnect the two fans installed on it, it doesnt boot --> fans are not the problem (but one of them smell as it had burned)!.

If I connect the riser, but disconnect the memory dimms, it doesnt boot --> memory dimms are not the problem.

How can I know where commes the problem?

It can be the second CPU board

It can be the second CPU

It can be the power supply, unable to give enough power for second CPU.

I dont want to buy any part if I'm not barely sure of what I have to change...

Thanks for Help!

If I connect the second cpu board, but disconnect the memory sticks, it doesnt boot --> memory sticks are not the problem.

How can I know where commes the problem?

It can be the second CPU board

It can be the second CPU

It can be the power supply, unable to give enough power for  second CPU.

[Brian1965]

As you correctly pointed out, the fault is somewhere on the 2nd CPU riser board since your Z620 boots fine with the riser card removed.

A couple of points to consider;

1) The PC will not boot if you remove all the DIMM modules on the CPU riser - this is normal behaviour. You must have at least 1x DIMM memory module installed for each CPU before the system will boot.

2) The fans must be connected on the CPU riser board for the system to boot. Again, this is normal behaviour. The system will not boot if the CPU fan is not detected.

I would recommend you test your system with just 1x DIMM memory module on the CPU riser card and 1x DIMM memory module installed on the motherboard. Please refer to the Maintenance and Service Guide for the correct memory module loading order, i.e. the DIMM modules must be installed in specific memory slots for this configuration to boot.

The Maintenance and Service Guide can be found in the manuals section on the HP Z620 support page.

Did you make any changes to the system hardware, BIOS or software just prior to the fault happening?