Question How to troubleshoot 6 beeps no POST?

[CharlieLo]

I have an old HP Z800 workstation. I've enabled the Compute for PCIe-16 slots and now it's not booting anymore. It beeps 6 times and pause then beep again. There is no LED light on the power button. Here's what I have done so far to troubleshoot this error and it still beeps 6 times.

1. reset CMOS by removing the battery
2. remove cards from all the slots
3. remove memory card and leave only two sticks in

I don't even get to the POST screen. It starts beeping right after I press the power button. I'm not sure what else to test. I've also posted this same issue on HP forum but not one seems to have an idea. This Z800 was working fine until I try to install a Samsung 970 EVO SSD 1TB - M.2 NVMe and it wasn't detecting it as a boot drive. However, now, I can't even boot the computer anymore. Any help is much appreciated.

 

[delaro]

Remove the Evo, Reseat your GPU and reset your BIOS via removing the battery and see if you can boot off the old drive.

 

[CharlieLo]

In my first post, I already tried removing all cards (and that includes the Evo and GPU) from all the motherboard slots and remove the CMOS battery. I also pressed the reset cmos button on the motherboard as well and nothing works. It's not even past the POST so it's not going to boot from the old drive. I even replace with a new GPU and it's still beeping.