PC not posting with AMD Ryzen 7 5800X3D

Having a nightmare

My old motherboard died, so I had to get a new one.

I got a msi mag tomahawk b550.

My CPU is a AMD Ryzen 7 5800X3D, so the CPU didn't work out the box it wouldn't post. I put in an old CPU got the system too boot into windows and installed the latest bios on the motherboard.

Swapped CPU's still wont post, GPU fans go on max and get no picture.

The motherboard does list support for the 5800X3D on one of the BIOS updates, but I skipped that update and just updated to the most recent, did this also skip the support added or should that be included in newest update.

What I mean if I roll back to the specific update it states support for the 5800x3D would it work ?

Also to note, there was too much thermal paste applied, some is in the socket but doesn't seen to effect the older CPU, however my 5800x3D does have some on its pins. I need to carefully clean this off with isopropyl before trying again.

this is the paste on the CPU, reckon this is stopping it booting ?

Update, cleaned CPU with isopropyl it's spotless, no bent pins looks good.

Thing still won't post with it in

Try to never use beta or latest bios, they can be finicky. I would just try the bios (7C91vA9) the one dated 2022-03-23, that adds first original 5800x3d support. Also I think that board will update the bios without a cpu in it was well.

@04dcarraher: I rolled back to bios you suggested and still nothing

I also have an amd 9 5900x which won't post either, just the 7 2700

Took to a local Repair shop now as I'm out of ideas.

They mentioned it could be the ram, some types of Ram don't play well with those CPUs ??

Been thinking is it because I used the amd 7 2700 to flash the bios.

The revision date when I look at the bios is out by about a month on what it should be.

If I use Bios flash back think it work ?

@thehig1: ram would be more of an issue with the older cpu and motherboard chipsets. Flashing the bios would set to the ram settings to defaults,which would actually help the cpus. Have you tried booting the system and looking at the ez debug led indicator on the motherboard? any lights cycle or get stuck on cpu, ram vga? Have you tried pulling the cmos battery out of the motherboard for a good 10 minutes after a bios flash?

You could also try thoroughly douse the cpu socket with 90%+ isopropyl alcohol and blow out the socket making sure all contacts are clean as well. But you could try use using the bios flash back through rear usb without any cpu in the socket. Download and place the first bios released version that supports 5800x3d.

@04dcarraher: the led indicator stays on CPU.

The socket is clean, have cleaned it with isopropyl and the 2700 works fine so it's likely not the socket.

Going to see what the repair shop so as they have it now

@thehig1: Personally, I wouldn't waste money with a repair shop. I would just return that motherboard and try my luck with a different one. It clearly does not like the 5000 series CPUs if both the 5800X3D and 5900X are not working on it, but the older 2700 does. If the BIOS has been updated, reset and it is still being stubborn, it is time to switch it up.

@BassMan: repair shop sorted it.

They were correct about the ram, they installed ram they had in shop and the PC booted up the 5900X. Then they took their ram out and put mine back in and it booted up.

Now I have a working PC and a spare high end Ryzen CPU lol. Going to take the 5900X out and put the 5800X3D in as the extra cache gives me better frames in Rust (game I play 90% of the time)

Good that it is sorted out, but that is messed up that the RAM was causing the issue. That same RAM was working with that mobo and a 2700, but was not working initially with the 5800X3D/5900X. However, It now works after temporarily swapping different RAM. That is fucked up. No wonder why you couldn't figure it out and get it working. It makes no sense.

I would also choose the 5800X3D over the 5900X if gaming is the primary focus.

@BassMan: doesn't make any sense to me either, haven't swapped the 5800x3D back in yet so not 100% that CPU is working fingers crossed it is it's the better CPU gives me better frames in rust

I’m confused. You can’t install a 7800X3D on a b550 board. Do you mean 5800X3D and keep changing the name?

Yes, he keeps changing the name and even made up a new CPU... 7850X3D. LOL

@thehig1: most likely you didn't seat the ram properly in the socket. Its happened to me before, and it's annoying af.

@ghostofgolden: yeah sorry the am4 3d chip 7 5800x3D

Its a top secret am4 special chip that AMD personally sent me ?

wasn't this, as id re-seated the ram multiple times and when the repair shop got it they did the same and it didn't work until they used different ram they had in stock.

Also the debug light was flashing CPU not DRAM so it was having issues during its post checks before getting to the DRAM check.

Typically, you definitely want to always check the RAM. The reason being is a dead tech once told me it's usually the RAM first because the RAM has integration with the display and if a display doesn't show or post it's a definite a sign that it can be the RAM. I'm glad you got it figured out.