No Post -- Ryzen 3600

[Andremal]

I've built a new system, but it won't post. The system lights up and the fans spin when powered on, but no display appears. Sometimes (not every time) the monitor is woken from sleep but says "No Signal" immediately and goes back to sleep. Sometimes (again, not every time) the system reboots after ~20 seconds and will continue rebooting after every ~20 seconds of running until powered off. Sometimes these happen together, sometimes not. The LEDs on any plugged in peripherals do not light up either.

Specs:

CPU: AMD Ryzen 5 3600

Motherboard: ASRock B450M/ac

(I have not updated the BIOS, but according to ASRock's site and some posts online, Matisse CPUs are supported without an update)

RAM: 2 x 8 GB Gigabyte DDR4-2666

GPU: Gigabyte RTX 2060 Super

PSU: EVGA 550 W

 

I've already tried everything here except putting the GPU and RAM in another computer (I don't have another nearby I could use) and I have no debug LEDs or speaker. I've disconnected everything that isn't totally essential, reseated everything, etc. I was having this issue on a different motherboard (same model) and tried using a GPU and CPU I know work, but when that still didn't work I assumed the mobo was the problem since I noticed it's CPU retention arm didn't feel firm and didn't lock into place correctly, plus the box it arrived in was damaged.

I'm hoping I've just overlooked something extremely obvious.

[Slottr]

2 minutes ago, Andremal said:

(I have not updated the BIOS, but according to ASRock's site and some posts online, Matisse CPUs are supported without an update)

Update your bios

[Fasauceome]

16 minutes ago, Andremal said:

(I have not updated the BIOS, but according to ASRock's site and some posts online, Matisse CPUs are supported without an update)

I can't find this information on the product page, you'll probably need an update.

[SPARTAN VI]

This is what OP is referring to: 

 

It appears this is a newer B450 board, its initial release was in June 2019 and there are only two BIOS versions. It appears it's meant to support Ryzen 3000 (and earlier) right out of the box.