HP Z2 Mini G9 – Boot issue with two DDR5 5600 MHz modules after BIOS 3.05.01 update

[Denony]

Hello,

I’m experiencing a boot issue with my HP Z2 Mini G9 (86C28EA) immediately after updating the BIOS to latest version 3.05.01.

Symptoms:

• The system fails to boot when two SO-DIMM DDR5 5600 MHz 16 GB modules are installed. Both modules are Sk Hynix HMCG78AGBSA095N)
• No display appears, and the system does 3 long beeps and 2 short beeps, indicating a memory error.

The system boots normally (with new BIOS  BIOS 3.05.01) with : 

• a single DDR5 5600 MHz module
• one of the DDR5 5600 MHz module and one DDR5 4800 MHz module (tested with a 8 GB module).

So I was able to downgrade to BIOS 3.04.08 (fortunatly 😀).  

Notes:

• The issue occurs immediately after installing BIOS 3.05.01.
• I tried to perform a CMOS reset and swap memory modules in slots : no fix.
• Downgrade to previous BIOS version (3.04.08) resolves the issue.
• Both memory modules passed "Memory Extensive Test" in HP PC Hardware Diagnostics UEFI
• The changelog for BIOS 3.05.01 doesn’t mention any changes related to memory.

I suspect a bug or compatibility issue affecting dual-channel DDR5 high-frequency configurations.

So, I downgraded to BIOS 3.04.08, which allows normal boot with both DDR5 5600 MHz modules, and the computer works fine with this older BIOS. I also selected "Lock BIOS Version" in BIOS settings to prevent Windows Update to ugrade to firmware 3.05.01 and bricks the computer.

Has anyone else experienced this issue with BIOS 3.05.01?

How to know if HP is aware of this and working on a fix ? IIs there a way to contact HP by mail ?)

Thanks in advance for any feedback or advice.

Best regards,

Note : RAM modules information (PowerShell> Get-WmiObject win32_physicalmemory)

Manufacturer	clockspeed	Devicelocator	Capacity	Partnumber
Hynix/Hyundai	5600	DIMM1	17179869184	HMCG78AGBSA095N
Hynix/Hyundai	5600	DIMM2	17179869184	HMCG78AGBSA095N

[Denony]

Hello 

To give you an update on this problem ! 

I opened a support ticket with HP for this problem 7 weeks ago.

They asked me to send them photos of the RAM modules and logs generated by HP diagnostic tools. They found nothing bad. 🙄

They tried to reproduce the problem on an "identical" configuration, but they couldn't.😮

So, they sent a technician to replace both RAM modules, but that didn't solve the problem.

Then he replaced the motherboard (with a most recent manufactured unit), and the problem disappeared.😀

The HP technician who came to replace the memory and motherboard told me he didn't understand the problem: he thinks there might be an incompatibility between my motherboard unit and the new firmware 3.05.01.

[Denony]

Hello

HP has just released a new firmware version: 3.05.02.

Here is the changelog:

Fixes an issue where the Z2G9 Mini J40 M2 slot PCIE speed limit is reported only to Gen3.

NOTE: HP strongly recommends transitioning promptly to this updated BIOS version.

• Adds Telemetry support for HP remote system controller.
• Provides supports for a new NVIDIA Graphics Card.
• Provides enhanced SODIMM support

Last point of the changelog makes me think that HP knew that there were problems with some SODIMM on some motherboards and that this firmware might have solved my HP Z2 Mini G9 problem with firmware 3.05.01.