My Z620 suddenly won't boot

[Brian1965]

You could try reloading the BIOS on the board and then updating to the latest BIOS version via the USB stick method, i.e. don't update the BIOS from within Windows. NOTE: Reloading the BIOS is not the same as resetting or clearing the BIOS. There's an excellent post created by SDH which details this procedure;

https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Crisis-Recovery-Ju...

[cmumu]

I think I have a similar issue to this with a fleet of Z440's. The symptoms are no post boot screen, doesn't get to the HP logo at all, and only shows a single period character in the top right. Our machines are bitlockered but that doesn't seem to make any difference. I've determined that the issues seems to only occur when an LED keyboard is present before it post's boot, the only way we've been able to resolve is to unplug the keyboard and plug it in once the bitlocker screen is active. This does not happen on every one of our z440's but unplugging the keyboard resolves the issue every time.

[SDH]

Brian.... I noticed that OP never answered you about whether he had possibly induced BIOS corruption by updating BIOS.  To others..... there has been a spate of bricking of HP workstations by updating BIOS from within the operating system, especially if that OS is W10.  The HP BIOS updaters include a utility that was designed for XP, then W7, but never for W10. 

I used that utility to update BIOS from within XP and W7 in the past but then learned the HP method of updating BIOS from within BIOS.  I switched over to that method for several years, but then I personally took a shortcut of updating a Z620 running W10.  I used the utility and corrupted my BIOS, bricking a very nice Z620.  Hence the creation of the post Brian links to above, and the steps I took that saved that Z620 v2 workstation.  I added a note today to it about a guy in another post here who succeeded in clearing the corrupted BIOS and loading in a good copy from a CD-ROM after failing with the standard USB method.  That might be a stripped down path to try if the USB approach fails, and it makes some sense that corruption of BIOS might kill one recovery path but leave another open.

For everyone:  learn how to update BIOS from within BIOS.  Layers of code (the operating system) are removed from this process if you do it that way.

Regarding the possible link of very odd workstation behavior to USB keyboards noted in this thread...... Any time I'm having to fix a mess, and whenever I clean load an OS, I'm sure to be using a PS2 keyboard and mouse.  You can get these easily brand new, HP brand, at low cost off eBay.  For the Z440 owner..... I'd get one of those keyboards and even a HP PS2 laser mouse to see if that helps.  My instinct is that it will given what you described.  I'd rather have a keyboard/Z440 that works than a nicely lit-up keyboard and a workstation that does not work.  I'm thinking that would not be a likely source for BIOS corruption, however.  Rather, a subsystem issue due to keyboard not being up to HP specs.

Corruption of BIOS does not only happen by a virus or a blown BIOS update...... electrons can do it too, and even bad luck and a cosmic ray.... see  .HERE.

https://science.slashdot.org/story/17/02/19/2330251/serious-computer-glitches-can-be-caused-by-cosmi...

Cmumu.... please post back to us on this interesting issue.  Thanks.

[VABludawg]

I had same problem no post, no screen, no beeps, no boot. I removed the 2nd CPU card and the system booted up fine. I’m glad it boots, but unhappy I have a cooked 2nd CPU card 😞

[DGroves]

did you by chance modify the bios's "Compute" setting?

if not does the system startup and then do the fans ramp up to full speed with a blue light?