HP ProDesk 405 G6 (DAF92MB26B0 Rev B) – CPU upgrade to Ryzen 3 4300GE requires 32MB BIOS chip. Has anyone successfully swapped the 16MB chip for a 32MB one and flashed S27?
Hi r/homelab,
I’ve got an HP ProDesk 405 G6 Desktop Mini PC (motherboard DAF92MB26B0 Rev B) that originally came with an Athlon Gold PRO 3150GE and a 16MB BIOS chip (Winbond 25Q128JVSQ). I wanted to upgrade to a Ryzen 3 4300GE, which is officially supported on this model, but only with BIOS version S27.
The problem:
· Current BIOS is S25 (Ver. 02.23.00), which only supports 3000-series CPUs.
· S27 requires a 32MB BIOS chip. My board has a 16MB chip, so a simple BIOS update is impossible.
· After swapping in the 4300GE, I get the error code 7 red / 5 white (which HP documents as "ROM detected failure prior to video").
· I tried running HP’s Firmware Update utility, but it won’t cross-flash from S25 to S27, and it reports no change.
My research so far:
· On vlab.su, a user with a similar board (DA0F92MB6F0 Rev F) tried replacing the 16MB chip with a 32MB MX25L25673G and flashing an S27 dump. It didn’t work – they got 6 red / 3 white instead.
· Another user confirmed that S27 contains different SMU firmware for 4000-series CPUs.
· I’ve found a 32MB S27 dump for my board revision.
· My plan is to replace the 25Q128JVSQ with a Winbond W25Q256JVEIQ (32MB, WSON-8) using a CH341A programmer and a WSON8-to-DIP8 adapter.
My questions:
Has anyone successfully performed this exact swap on a 405 G6 (or similar HP mini PC)? If so, what was your procedure?
Besides the main BIOS chip, is there anything else that needs to be modified? I noticed there’s also a 4MB EC chip (MX25L3255E) on the board. Could that be involved?
Are there any specific steps needed when flashing the 32MB dump – e.g., preserving the board’s serial number, MAC address, or other descriptors? I’ve read that HP BIOS images often contain a descriptor region and ME region that might need to be transferred.
If the swap fails, are there any alternative workarounds (e.g., using a different CPU that works with S25, or modifying the S25 image to add 4000-series support)?
I have a CH341A programmer, a WSON8 adapter, and the 32MB dump ready. I’m willing to try, but I’d like to know if there’s a known working method before I risk bricking the board.
Any insight or experience would be greatly appreciated. Thanks!