Question How to confirm that the motherboard is faulty ?

[opeydopey]

Hi all,

I recently replaced my old TaiChi X370 motherboard with an ASUS TUF Gaming B550M-Plus WiFi II.

Other components from the old machine include a Ryzen 7 3700X, two sticks of Vengeance 16GB 3200C16, and a Radeon RX 5700.

All has been running beautifully for almost a week. Then the graphics suddenly went dead (no artifacts, just off). I confirmed the monitor is good with another PC.
Trying to reboot, the POST beep codes (one long, two short) for the AMIBIOS indicate a video error but the DIMM error light is also lit. I have tried three different known good graphics cards and I get the same error beeps. Cleared the CMOS, updated the BIOS, reseated everything, still no POST at all and still getting the error beeps.

I seem to have narrowed down the issue to dual channel memory: if I just use one stick of RAM in any slot, it works fine. As soon as I have two or four slots filled, the fault light is on and I get the beeps. I can swap the RAM around and get it to boot into Windows with any of the sticks I've tried - as long as it's just one.

I've reseated the CPU, checked all cables, unplugged all peripherals etc.

Does this sound like a faulty motherboard?

Any other ideas of what to try? At the moment I'm inclined to return the mobo under warranty as I can't think of any other cause.

Cheers!

 

[boju]

How tight are you tensioning cpu cooler? An overtight cooler can cause memory issues putting too much stress on the cpu pins, try slacken off tension screws half turn backwards.

Probably is motherboard though since you had it going for a week. Symptoms with an overtight cooler would have been immediate.

What is psu model btw and how old? Probably not that but need to ask.

 

[opeydopey]

How tight are you tensioning cpu cooler? An overtight cooler can cause memory issues putting too much stress on the cpu pins, try slacken off tension screws half turn backwards.

Probably is motherboard though since you had it going for a week. Symptoms with an overtight cooler would have been immediate.

What is psu model btw and how old? Probably not that but need to ask.

Thanks for the advice.
The PSU is a Corsair CS750M. I'd say it's about 7 years old.
I'll try another one when I take the mobo out of the case.

 

[USAFRet]

In the context of this new motherboard, did you do a full wipe and reinstall of the OS?

 

[opeydopey]

In the context of this new motherboard, did you do a full wipe and reinstall of the OS?

No. Given that I was going from one AMD chipset to another, it didn't seem necessary.
Plus everything was working perfectly for nearly a week.
I can't even POST with two sticks of RAM so I didn't look at the OS as being likely.

 

[USAFRet]

No. Given that I was going from one AMD chipset to another, it didn't seem necessary.
Plus everything was working perfectly for nearly a week.
I can't even POST with two sticks of RAM so I didn't look at the OS as being likely.

Unless it is an exact replacement, AMD -> AMD doesn't matter.
Or Intel -> Intel.

A fresh OS is where I would start.

 

[opeydopey]

Update - replaced PSU with no change.
Re the OS - I don't even have any drives connected at the moment - I'm just trying to get it to POST with the bare minimum peripherals. Would the OS possibly prevent the POST sequence?

 

[boju]

Would the OS possibly prevent the POST sequence?

No it shouldn't.

 

[USAFRet]

Update - replaced PSU with no change.
Re the OS - I don't even have any drives connected at the moment - I'm just trying to get it to POST with the bare minimum peripherals. Would the OS possibly prevent the POST sequence?

With no drives, it should just stop at a fully functioning BIOS.