Z600 - POST beep error (Five (5) beeps)

[Dhorlo]

I bought a used Z600 Workstation with 12 GB of ram and dual Xeon E5520 cpus about a year ago. It's been running VMware esxi 6 like a champ, 24/7, without issue.  I made a change to esxi to enable hyper threading which I hadn't had enabled previously. The change required a reboot.

Directly after reboot, the Z600 gave an error of 5 beeps with power led switching from blue to red and blinking red with each beep. 

I found the Z600 Service Manual and the diagnostic code refers to a "Pre-video memory error".  I tried the following to resolve the error without success:

1. Reseat DIMMs.
2. Replace DIMMs one at a time to isolate faulty module.
3. Removed DIMMs power cycled system without DIMMs, and re-placed DIMMs, (this was a repair "technique" suggested on another post here in the HP forums for a "5 beeps" issue).
4. Replaced DIMMs with different compatible DIMMS.
5. Replaced system board with used, but identical part number motherboard and repeated steps 1-4. 

At this point, I don't know what else I can do from a troubleshooting stand point. 

Any help or suggestions would be greatly appreciated.

[Dan_WGBU]

5 beeps is usually a memory error.  You followed the recommended steps to determine if a bad DIMM is causing this problem.  

Step 5 says you replaced the system board with another.  Did you try to run it with 1 CPU installed?  

On the first board, did you try to clear CMOS?  (pull AC power cord for a minute, then press the yellow push botton)

[Dhorlo]

@Dan_WGBU, thanks for your reply and sorry for my late response.

I have not tried using only 1 CPU, but I'll remove the second CPU and give that a try. 

I did press CMOS reset button and removed the CMOS battery on both system boards as well (thinking that would insure clearing it).

I'll post what happens with removing the CPU, pass or fail.

Thanks.

[Dhorlo · Accepted solution]

Just a final follow up.

I removed the 2nd CPU, cleared the CMOS but it still POSTs with the 5 beep error. Swapped out all the sticks of RAM, swapped the 1st CPU with the 2nd and swapped out the RAM sticks again. Each combination had the POST error.

I'm throwing in the towel. I thought about buying new RAM since all my RAM is used, but I can't justify spending good money after bad on a hunch it's the RAM. I'm going to part out the Z600 and try to recoup some of my losses.

I just wish there was some other diagnostic method I could apply to figure out what the issue is.

Who knew rebooting, after a year of solid service, would kill the PC. 

Thanks everyone.