Question First TrueNAS build: Powers on but won’t POST (ASRock B550 Pro4)

[QuestionAsker]

My new build powers on (fans spin, LEDs on) but no POST / no video output.



What I’ve tried / observed:

• System powers on normally (fans, LEDs).
• No signal on monitor (HDMI/DP).
• No POST screen, no beeps.
• Tried booting with Ryzen PRO 4750G, and then with Ryzen 5 3600 + GPU… still no POST screen or anything

Hardware:

• Motherboard: ASRock B550 Pro4
• CPU (primary): Ryzen PRO 4750G (used)
• • One pin was bent when removed (now removed from system)
• CPU (test): Ryzen 5 3600 (used)
• GPU (with 3600): Gigabyte Radeon R9 390X
• RAM: 64 GB ECC UDIMM (2×32 GB Kingston KSM26ED8/32HC)
• PSU: Corsair RM850x

Notes / hypotheses:

• Suspect BIOS incompatibility with 4750G or damaged CPU pin.
• Even with Ryzen 5 3600 + discrete GPU, still no POST.

Next steps I’m considering:

• Test with a second (older) GPU
• Attempt to straighten the bent CPU pin on the 4750G (though it’s my first time doing that and I’m a bit nervous… it looks pretty bent)

Question:

What else should I try to isolate the cause (BIOS, RAM compatibility, board issue, etc.)?

 

[bba-tcg]

Try one stick of RAM at a time. Try each slot.

 

[Steltek]

It shouldn't be a BIOS compatibility issue, as the ASRock B550 Pro4 supported both the 3600 and the 4750G CPUs out of box at the time the board was first released per the ASrock support website. It also never required a later bridge BIOS that eliminated support for older CPUs in order to support Ryzen 5000.

Probably stupid questions, but:

1) Is this a new or used motherboard? Have you tried following the CMOS memory reset instructions?

2) Did you actually hook a buzzer speaker up to the motherboard speaker header to hear the post beeps?

3) Have you tried booting the system without the dedicated GPU installed, with the monitor cable plugged into the motherboard graphics port to see if the motherboard is defaulting to boot with the integrated iGPU on the CPU instead of the dedicated GPU? Forgot the 3600 doesn't have integrated graphics (haven't had one for a while now).

4) As a last resort, have you tried dismounting the motherboard from the case to see if you have a grounding issue? If not, pull it out of the case, place it on a cardboard box, install one memory module, plug the monitor cable into the motherboard graphics port, and short the power switch pins with a screwdriver. If it doesn't work with the first memory module, swap them and try again.

If you go through all of these steps without success, I'd guess you have either a bad motherboard or a bad PSU.

 

[QuestionAsker]

@bba-tcg @Steltek Thanks for your replies.

Are there any particular DDR4 RAM sticks you'd recommend for my system, that would be a solid choice, to get it to POST?

-----

Other stuff I've tried so far:

Unplugged everything besides fans and mobo / cpu power. (And power/reset switch connections, since they're blocked by one of the HDDs, which I was hoping not to remove (since it was a pain to mount it)).



Still no POST. Just CPU and DRAM error lights.



Left only 1 x 32GB ECC RAM stick in the A2 slot. Still same errors, no POST.



Cleared CMOS (removed battery for 20+ min). No POST.



When booting, let it run a few times for 15 min + to see if maybe it needed to train the memory. Still no POST.



I will buy one stick of 8GB consumer DDR4 RAM, on ebay, to get it to boot. Problem is I have no DDR4 system, so I have no way of testing whether it's a "known good" stick or not.



(I'm open to suggestions for best DDR4 8GB stick to get, that has highest likelihood of getting my system to POST).



Please let me know if you guys have any other ideas.



(I also bought a motherboard speaker, for better troubleshooting. Waiting for it in the mail).

 

[bba-tcg]

For testing, any DDR4 memory should work. I've had great luck with G.Skill. DDR4 doesn't train like DDR5.

 

[Steltek]

Unless you have unsuccessfully tried both modules in the A2 slot or otherwise have a reason to believe the memory modules might both be defective, I don't think it this is going to turn out to be a memory issue. To be sure, try each module one at a time placed in every memory slot to see if it might be a bad memory channel on the CPU memory controller.

While Kingston KSM26ED8/32HC modules are not specifically listed in the ASrock motherboard Matisse QVL list, Kingston KSM26ED8/32ME modules are on the list. The only difference between the two is that the ME variant uses Micron E-die memory chips while the HC variant uses SK-Hynix C-die. The operating specs of both the HC and ME modules are absolutely identical, so either should work as well as the other.

If you want to buy an 8GB module to guarantee absolute compatibility, make sure to pick one that is listed in the ASRock Matisse QVL list (the Ryzen 5 3600 is a Matisse CPU).

@bba-tcg is right, though, as any decent module installed in the board should at least post.

Personally, I'm leaning more towards either a bad motherboard or bad CPU at this point (i.e. there were a significant number of 3600 CPUs that had poor/defective memory controllers).

Note: If you do get a 4/8GB module and it does boot, you might update the BIOS on the motherboard to see if it improves the memory compatibility of the motherboard.

 

[DAPUNISHER]

A quick search will turn up videos of how to fix bent pins. It is useless as is, so it is worth the risk to straighten it. I use an old credit card I shaved even thinner on the edge, and for certain ones, a toothpick. All of the popular methods will work. I have not broken a pin off of any of the CPUs brought to me, or that I bought that way. You should be fine.

While obviously you want to get the system running. I took a quick look, and that board works with ECC UDIMMs but there are users saying it fails to report any errors to the OS.

For troubleshooting, I suggest you use a super cheap slot powered card like a Quadro p600 from Ebay. It never failed me.

 

[Steltek]

I never tried it, but I've read you can use a 0.5mm mechanical pencil to straighten the pins. I've been lucky so far that the only pins I ever had to straighten were on the outside edges and could be straightened with tweezers.

A person I knew a few years ago told me once that he actually uses 23 gauge hypodermic needle syringe tips as they are only fractionally larger than Ryzen CPU pins. He said he slides the bent pin into the needle, then uses a heat gun or soldering iron to heat the needle with the pin inside it - he said heating the pin a little makes it more elastic and thus easier to bend without snapping. You just have to be careful not to use so much heat that you desolder the pin from the CPU. He then uses an old metal Amazon Prime card to align the bent pins with rows if needed after straightening them.

He also had some type of AM4 stencil that he used to check the pin alignment before actually installing the CPU in the socket. I didn't think to ask him exactly what it is and where he got it; it might just have been an AM4 reballing stencil, but I honestly don't know for sure.

 

[bba-tcg]

I generally use a knife blade to slide between the rows and gently twist the bent pin back into place.