Asrock X470D4U server board.

[pc1staid]

Hi all. I cant find a forum for server boards so if this post is in the wrong forum, would an admin please move it the correct one.

I have a customers board here that was working fine pre upgrade with another CPU.
The CPU that was in situ and working fine was an AMD Ryzen 7 3700X. It was upgraded with a AMD Ryzen 7 Pro 4750G. To make this work the BIOS needed upgrading as well. Stock was version 3.10, was upgraded to 3.30 then for this CPU upgrade it was raised to 3.50. When the reflash had finished, a report that it completed successfully was seen ( not done by me, by the customer). Since then, the board fails to POST.
There is a POST reader on the board that initializes with 00 then follows this course:- 33-72-36 ( hanges for 30 secs)-90 then starts to count down in increments of -1 every second till it reaches 01 ( hangs for approx 60 secs) the reboots following the same sequence.
This happens with the new, old CPU, the original 32GB RAM and replaced the RAM with 16GB (2x 8gb), onboard and dedicated GPU, original PSU and a Corsair 850w 80+ Gold PSU.

I have also reflashed the BIOS with a clean 3.50, then back to 3.30 and back to the original 3.10... even gone back as far as the initial 1.20. I have looked on the QVL for the CPU's and the board does support the 4750G but from BIOS revision P4.20, however this BIOS revision is not available on the Asrock site.

I have taken measurements across the board via the links (PL's) and I get 0.9/1.2/1.8/3.3/12v readings. There is one link that gives me 2.4v but I have no 5v. Yet a chipmunk in the USB shows I do have 5v there. I also have a good 5v on the PSU, yet nowhere else is there a 5v reading. I have traced back the 5v as best I cant from the USB but I seem to lose it via the layers.

There is no schematic available. On the link I feel should be the 5v rail there is a reading of 030v in diode mode which I feel is a little low, there is another link in very close proximity that has the same component layout ( caps/ resistors) that is the 1.8v rail and that also reads around the 030v. So whilst I feel this is the 5v rail I can not be certain and therefore at this point I do not want to inject voltage in to see if/ where a short maybe.

I feel there is no direct corrolation between the BIOS upgrade and the no 5v detection on the board and it maybe just coincidental.

I am a little stumped now. Details on the board can be found here:- https://www.asrockrack.com/general/p...Specifications

Any pointers that may help me are greatfully recieved.
TIA

[pc1staid]

Anyone???

[waldoalvarez00]

I think you better find out what those codes in the led display mean. Should be in the board manual.

[waldoalvarez00]

https://download.asrock.com/Manual/X470D4U.pdf

0x36 PEI_CPU_SMM_INIT

https://en.wikipedia.org/wiki/System_Management_Mode

0x90DXE_BDS_STARTED (that means that is trying to boot)

I saw some ppl on another forums trying with video card and even one guy cooling with a fan the chip that reads aspeed.

[Exim]

Originally Posted by pc1staid

I have looked on the QVL for the CPU's and the board does support the 4750G but from BIOS revision P4.20, however this BIOS revision is not available on the Asrock site.

There's a 4.21 Beta: https://download.asrock.com/BIOS/Ser...(L4.21)ROM.zip