ASRock Rack SP5 nightmare: 2 motherboards, 2 EPYC 9254s, 2 PSUs, still no host power

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raptorbeaver

New Member
Mar 15, 2025
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I'm completely stuck and would really appreciate input from people familiar with SP5, ASRock Rack, EPYC Genoa, AST2600/BMC behavior, or server power sequencing.

Hardware tested
Motherboard #1
ASRock Rack GENOAD8X-2T/BCM

Motherboard #2
ASRock Rack TURIND8-2L2T

CPU #1
AMD EPYC 9254 (Genoa, 24-core)

CPU #2
AMD EPYC 9254 (different physical CPU, different seller)

RAM
SK Hynix DDR5 ECC RDIMM
64GB
HMCG94MEBRA103N
PC5-4800B

PSU #1
Seasonic PRIME TX-1600 Noctua Edition

PSU #2
Another TX-1600 unit with different cables

Symptom
The symptom is IDENTICAL across both motherboards and both CPUs.

BMC works perfectly:

  • IPMI accessible
  • sensor page accessible
  • firmware updates work
  • login works
  • UID button works
Host does not:

  • no fan spin
  • no Dr.Debug code
  • no VGA output
  • no POST
  • no power-on
Power button does nothing.

IPMI Power On gives:

Performing Power Action.. Please Wait
Retrying...please wait. Retries Left : 2
Retrying...please wait. Retries Left : 1
Performing power action failed.

Host never enters ON state.

What I tested
Motherboards
  • GENOAD8X-2T/BCM
  • TURIND8-2L2T
Same behavior.

CPUs
  • EPYC 9254 #1
  • EPYC 9254 #2
Same behavior.

Power supplies
  • TX-1600 #1
  • TX-1600 #2
Same behavior.

Memory
  • full population
  • 1 DIMM in A1
  • no DIMMs installed at all
Same behavior.

Build configuration
  • inside chassis
  • outside chassis on cardboard
  • minimal config
Same behavior.

Cooling
  • Arctic SP5 cooler installed
  • cooler removed
  • tested without cooler for power sequencing
Same behavior.

CPU installation
  • CPU always kept in carrier
  • followed SP5 rail/carrier procedure
  • inspected sockets carefully
  • no obvious bent pins
  • used torque screwdriver
  • tested around 1.5 Nm
Firmware
  • BMC updated
  • BIOS updated on GENOAD8X
Interesting observations
TURIND8 sensor page
Only standby rails exist:

  • 3.3VSB present
  • 5VSB present
Everything host-related is disabled:

  • VCORE disabled
  • VSOC disabled
  • VOLT_12V disabled
  • TEMP_CPU disabled
  • POWER_CPU disabled
  • all fan sensors disabled
  • all DDR5 sensors disabled
This makes it look like the host power domain never comes up.

System Inventory
Processor Info:

Information Not Available

No CPU information shown.

LEDs
  • Standby power LED active
  • BMC heartbeat active
  • Dr.Debug completely dark
No POST code ever appears.

Why I'm confused
At this point I have changed:

  • motherboard
  • CPU
  • PSU
Yet the behavior is bit-for-bit identical.

That makes me think this is either:

  1. a very specific SP5 platform issue
  2. some CPU presence / host power sequencing failure
  3. something obvious that I'm completely blind to
What I cannot explain is why:

  • two different SP5 boards
  • two different EPYC 9254s
  • two PSU units
all fail in exactly the same way.

Has anyone seen:

  • Processor Info unavailable
  • all CPU sensors disabled
  • BMC fully alive
  • host power retries and fails
  • Dr.Debug completely dark
on EPYC SP5?

Any ideas appreciated.
 
R

RolloZ170

Well-Known Member
Apr 24, 2016
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raptorbeaver said:
Has anyone seen:

  • Processor Info unavailable
  • all CPU sensors disabled
  • BMC fully alive
  • host power retries and fails
  • Dr.Debug completely dark
Click to expand...
inventory needs POST to show.
CPU sensors are dead in OFF state.
Dr.Debug comes after press PWR-BTN normaly.

CPU rotated 180degree in carrier ? (happend before)
 
R

raptorbeaver

New Member
Mar 15, 2025
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RolloZ170 said:
inventory needs POST to show.
CPU sensors are dead in OFF state.
Dr.Debug comes after press PWR-BTN normaly.

CPU rotated 180degree in carrier ? (happend before)
Click to expand...
Thank you so much for your quick answer.

After ~15 minutes powered on, fans started automatically and Dr.Debug became active.

The board now consistently reaches POST code 00 and stays there indefinitely (since 30 mins)

Fans spin at high speed.

BMC still reports Host Offline.

KVM still says Powered Off.
 
R

raptorbeaver

New Member
Mar 15, 2025
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Update:

After leaving the system powered for ~50 minutes:

- fans started spinning by themselves (after 15 mins)
- Dr.Debug became active
- code is 00
- code remains 00 indefinitely
- BMC still reports Host Offline
- KVM still reports Powered Off

No power button press.
No IPMI Power On command.
 
T

TrashMaster

Active Member
Sep 8, 2024
116
87
28
This smells of cpu mounting pressure/alignment problems or a short to ground somewhere like a standoff touching the bottom of the motherboard where there is no hole.
 
T

TrashMaster

Active Member
Sep 8, 2024
116
87
28
He would need to post a detailed high def video of the whole setup and process. i have too many friends unfamiliar with this kind of hardware reporting all kinds of weird self inflicted problems on discord.
 
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RolloZ170

Well-Known Member
Apr 24, 2016
10,062
3,227
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germany
TrashMaster said:
his smells of cpu mounting pressure/alignment problems
Click to expand...
raptorbeaver said:
Cooling
  • Arctic SP5 cooler installed
  • cooler removed
  • tested without cooler for power sequencing
Click to expand...
well have overseen: this Arctic does not align well, and surface not matching cpu IHS. try other cooler.
Cooler removed ?
tested without cooler ?
only the cooler presses the CPU in the socket, this is not SP3 !
 
K

Kizune

Member
Dec 2, 2022
96
69
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I cannot say for ASRock - but i do have Supermicro motherboard (H14-SSL-NT to be precise) and it does not POST with memory slower than 5600. With known working 4800 it does power on but POST does not start - even BMC does not come online.
 
R

RolloZ170

Well-Known Member
Apr 24, 2016
10,062
3,227
113
germany
Kizune said:
but i do have Supermicro motherboard (H14-SSL-NT to be precise) and it does not POST with memory slower than 5600. With known working 4800 it does power on but POST does not start
Click to expand...
strange unexpected behave. i have X14 and i get a warning "memory not supported my memory controller" with 4800 and 5600 RAM but it works fine.
Kizune said:
even BMC does not come online.
Click to expand...
should work even without RAM & CPU.
 
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