CPU debug LED and no post after assembling in case

[ManEatingFridge]

B450 Tomahawk

R5 3600

RTX 2080

2x8 DDR4 3200 CL16

 

Assembled everything on the mobo box, flashed to the latest BIOS. Didn't post, mobo rgb was glowing white and cpu debug LED was solid red, fans spinning, no shutdown or anything it just stayed like this. Somehow switching the RAM sticks around (A2 to B2 and B2 to A2) fixed it.

Boot sequence was that the mobo RGB would turn off, then solid red and debug LEDs would go CPU, skip DRAM straight to VGA and then BOOT. Got into BIOS just fine, everything detected.

I then assembled the build into the case and low and behold no post again with the same symptoms as before. This time no RAM swapping or anything is helping. Tried clearing cmos and flashed an older bios, still nothing. Tried booting 20 times in a row. Still nothing.

 

Wat do?

[ELSknutson]

could you snap some pictures of the inside?  also did you dubble check to see if your CPU power cables are seated properly. 

[TVwazhere]

4 minutes ago, ManEatingFridge said:

Wat do?

Try booting with only 1 stick

[ManEatingFridge]

2 minutes ago, TVwazhere said:

Try booting with only 1 stick

Tried one stick and every slot. Maybe the wrong stick, I have another 2x16GB set of DDR4 so maybe I should try that?. Doesn't seem relevant though, since when I got it to boot it recognized both sticks in A2 and B2.

[ManEatingFridge]

6 minutes ago, ELSknutson said:

could you snap some pictures of the inside?  also did you dubble check to see if your CPU power cables are seated properly. 

Cpu cables are good

[TVwazhere]

Well make sure you're back up to an up-to-date BOIS that supports Zen 2 architectures. 

The CPU debug LED is stuck on CPU?

[ManEatingFridge]

2 minutes ago, TVwazhere said:

Well make sure you're back up to an up-to-date BOIS that supports Zen 2 architectures.

I flashed to 07/10 as a sanity check but I'm flashing back to 07/22 just in case it works somehow.

3 minutes ago, TVwazhere said:

The CPU debug LED is stuck on CPU?

Yes the CPU LED is solid red

[TVwazhere]

Just now, ManEatingFridge said:

Yes the CPU LED is solid red

Then it would suggest the issue lies somewhere with the CPU; either not being detected or there's something wrong with the CPU. Bent pin, or maybe installed wrong. If you have extra thermalpaste, I'd unmount the cooler, clean it and double check the mounting.

[ELSknutson]

try backing off the cpu cooler half a turn 

[YoFavRussian]

1 minute ago, TVwazhere said:

Then it would suggest the issue lies somewhere with the CPU; either not being detected or there's something wrong with the CPU. Bent pin, or maybe installed wrong. If you have extra thermalpaste, I'd unmount the cooler, clean it and double check the mounting.

The worst part about testing a problem like this is that it can be a failing/bad motherboard as well. It does good to have extra parts that you can use to troubleshoot.

 

[ManEatingFridge]

Yeah so somehow flashing back to the latest BIOS after clearing CMOS got it to post no issues. I rebooted a bunch of times to check and everything is detecting and working properly. I'm glad this isn't my system because what in the actual fuck.

 

EDIT: Actually no. After doing some cable management the issue repeated. I then reflashed the BIOS again and got the system to post. After a while I got the same issue again. Should I just RMA the motherboard?

Edited August 21, 2019 by ManEatingFridge