RAM beep code error only when warm restart from Windows.

[CRNK]

Product: HP Z2 Tower G5 Workstation (259J7EA)
BIOS version: S50 Ver. 01.04.18 10/04/2024
OS: Windows 11 24H2, Build 26100.6584

The workstation fails POST with a 3 long / 2 short beep code (memory error) on every Windows restart. Cold boots (shutdown > power on) and BIOS-initiated restarts are always successful.

This is 100% reproducible:
Cold boot (shutdown > power on) = POST success.
Restart from BIOS Setup (Save & Exit BIOS > Restart) = POST success.
Restart from Windows (any build, normal or Safe Mode) = POST always fails with 3 long / 2 short beeps.

Steps Already Taken:

- Tested each DIMM individually in each slot. Same failure pattern regardless of stick or slot.

- Swapped DIMMs between channels

- Verified behaviour with multiple RAM modules (not a DIMM issue).

- CMOS reset performed via onboard button.

- Disabled Fast Start-up in Windows and Fast Boot in BIOS.

- Flashed BIOS to latest version from HP support site (and reset to defaults).

- Updated chipset and Intel Management Engine drivers to latest HP versions.

- Verified that BIOS-initiated restarts succeed 100% of the time.

- Verified that cold boots succeed 100% of the time.

- Tried with minimal hardware (1 DIMM, no peripherals, spare drive).

I have recordings of booting from a restart vs booting from a shutdown though I can't seem to upload on here.

From what I know it seems like there is something wrong with the memory controller.
I can't seem to find anybody else with this specific issue.

Any other information can be provided on request.

[NonSequitur777]

@CRNK,

Welcome to our HP Community forum!

If I may: you have done an outstanding job of isolating the problem -especially confirming that cold boots and BIOS-initiated restarts always succeed, whilst Windows-initiated restarts consistently trigger the 3 long / 2 short memory beep code. That distinction is very important.

Since you’ve already swapped/tested DIMMs, cleared CMOS, updated BIOS/ME/chipset, and disabled both Fast Boot options, this looks less like a DIMM fault and more like a firmware/BIOS handoff issue during warm restarts. A couple of things you might still try:

1. Check BIOS power settings:

   • Under Advanced → Power Management, try toggling “Deep Sleep” or “ERP” modes if available. Some restart handoff issues are linked to how power rails are sequenced.

2. Test with different restart paths:

   • Try running: shutdown /r /fw /t 0 from Windows (this tells Windows to restart directly into firmware). If that succeeds 100%, it helps confirm it’s the OS-to-firmware transition rather than the hardware.

3. Memory remapping / ECC settings:

   • If available in BIOS, toggle “Memory Remap Feature” or ECC enable/disable (depending on your DIMMs). Sometimes POST misreads timing on warm starts.

4. Try a clean restart with Fast Startup service fully disabled:

   • You already disabled Fast Startup in Control Panel, but also check that the Windows “Hybrid Boot” service isn’t forcing a semi-hibernate state. Run:

     powercfg /h off

     and test restarts again.

5. HP Support angle:

   • Since this is a workstation-class system (Z2 Tower G5), HP may need to release a BIOS fix if it’s reproducible. You’ve gathered excellent data -I’d suggest opening a support case with your notes, as this looks more like a BIOS/firmware bug affecting Windows restarts than a hardware failure.

It's sort of a longshot, but here’s how you can try to open a support case with your notes and test results:

1. Go to HP Customer Support – Contact.

2. Enter your Product Number (259J7EA) or let the site auto-detect.

3. Select your operating system (Windows 11).

4. Choose “Get help from HP” → “Chat with HP” or “Submit a case” (options vary by region).

5. Provide your system’s serial number (on the side of the case).

6. When prompted, paste in the troubleshooting you’ve already done (DIMM swap, CMOS reset, BIOS update, etc.).

That way, the HP engineer reviewing your case can see you’ve already ruled out the usual suspects and may escalate to a BIOS/firmware investigation rather than starting from scratch.

Kind Regards,

NonSequitur777

[CRNK]

@NonSequitur777,

Thank you for your kind words, interest and support in my case.

I have gone through your troubleshooting steps and unfortunately every step of the way the PC still fails, including the command to restart to firmware from windows which I thought would succeed.

1. Performing a Windows restart after toggling fails, displaying the same beep code as mentioned.
2. Restarting from Windows going directly into firmware fails, displaying the same beep code.
3. Restarting from Windows after toggling fails, displaying the same beep code.
4. Disabling hibernation from CMD line and then rebooting fails, displaying the same beep code.

Though I appreciate your support, This may be something that needs to go through HP Support directly.

I will see if I can get a ticket raised with them though I'm not sure if they will consider supporting me as the device ran out of warranty at the beginning of the year.

If there are any more suggestions I am open to trying just about anything at this point as it is a very peculiar issue, nothing like I have seen before, that I would like to get resolved.

[NonSequitur777]

@CRNK,

I'm afraid I have shared everything I can regarding this matter.

Yes, it seems that your case may need to be handled directly by HP Support.

Warm Regards,

NonSequitur777

[Rainer_Eder]

Had the same trouble that rebooting from Windows ended in three long (LED red) and 2 short (white LED) beeps.

Shutdown / Power On and rebooting from BIOS was no problem.

I was able to fix this issue by disabling "Virtualization Technology (VTx) and "Virtualization Technology for Directed I/O (VTd)" in BIOS - Advanced - System Options.

HTH