Question CPU led on for few seconds then it turns off and the video LED turns on

[Star2222]

Hi,
I have a brand new Tomahawk MSI MAG B550 ATX with brand new Ryzen 9 3900x. System just assembled but when turned on the CPU debug LED cames on for few seconds (maybe 20 seconds) then it turns OFF and then the graphics led comes on and stays on. All components are brand new.

That happens both plugging in the monitor into the motherboard HDMI (without graphic card) as well as installing an old-ish graphic card and plugging the monitor into that one.

I tried various checklists posted even here but haven't yet found a solution.

Could someone please help with the following:

1. What could it be and how can I solve it?
2. if I reset the BIOS with the jumper on the motherboard, is it 100% guaranteed to work with that specific CPU?
3. What does that combination of LED sequence (CPU on then off and then graphics on permanently) mean and how can I solve it?
4. Is the CPU led supposed to turn on for few seconds at boot or not at all?

The full system components is listed below.

Thank you

CPU: Ryzen 9 3900x (bought in Sept 21 from Amazon but sat there sealed in its box until today)
Motherboard: Tomahawk MSI MAG B550 ATX (also bought in Sept 21 from Amazon but sat there sealed in its box until today)
Ram: Patriot Viper 4 Blackout Series DDR4 32GB (2 x 16GB) 3200MHz Kit
SSD/HDD: WD_BLACK SN750 1TB M.2 2280 PCIe Gen3 NVMe Gaming SSD up to 3430 MB/s read speed
GPU: AMD Firepro Graphics 5000
PSU: BeQuiet BN283 Straight Power 11 750W ATX
Chassis: Pure Base 500DX
OS: None...
Monitor: Various all using HDMI

 

[Lutfij]

MSI have a number of Tomahawk boards, which one do you have? If you have the Max or the latter version Max II, then you should be able to work with a RyZen 3000 series processor out of the box, but I'm assuming you don't have a discrete GPU in your build.

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. Please list them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:
Monitor:

Please mention the age of the PSU apart from it's make and model, if it's a recycled unit(from a former build).

 

[Star2222]

Thank you @Lutfij

If by "discrete GPU" you mean a separate PCIe card then I tried with both an older card (the one listed in the specs) as well as just plugging the monitor into the motherboard HDMI.

I updated the OP with that info. Also see below:

CPU: Ryzen 9 3900x (bought in Sept 21 from Amazon but sat there sealed in its box until today)
Motherboard: Tomahawk MSI MAG B550 ATX (also bought in Sept 21 from Amazon but sat there sealed in its box until today)
Ram: Patriot Viper 4 Blackout Series DDR4 32GB (2 x 16GB) 3200MHz Kit
SSD/HDD: WD_BLACK SN750 1TB M.2 2280 PCIe Gen3 NVMe Gaming SSD up to 3430 MB/s read speed
GPU: AMD Firepro Graphics 5000
PSU: BeQuiet BN283 Straight Power 11 750W ATX
Chassis: Pure Base 500DX
OS: None...
Monitor: Various all using HDMI

Thank you