New cpu. Now pc doesn't display anything.

[unwashed potato!]

The pc turns on as the fans spin, but nothing happens after this. No display, no USB work, the USB items like dongles don't even have any lights on them any more

I've no idea how I would diagnose those as very little has changed.just took out the old cpu, put in the new one and the new heatsink, plugged the cpu fan in and that's it.

Could it be that the cpu needs more power now than the last?

There is a 4 pin next to the cpu plugged into a area that actually has 8 pins available but only 4 were ever used. Not sure why only 4 out of 8 were needed. Would a weaker cpu only want 4?

 

[Oh Ed not again.]

What board and CPU?

 

[unwashed potato!]

3900x

Gigabyte AB350-Gaming 3-CF

 

[Oh Ed not again.]

Bios up to date?

Pop the old CPU back in and upgrade it if needs be.

 

[unwashed potato!]

I've never myself updated it.

How would I go about doing that?

 

[Quartz]

@randal is almost certainly correct. But so are you. Put your old CPU back in. Update the BIOS. Plug in a full 8 pin EPS power connector. Then put in your new 3900.

 

[unwashed potato!]

removed

 

[unwashed potato!]

@randal is almost certainly correct. But so are you. Put your old CPU back in. Update the BIOS. Plug in a full 8 pin EPS power connector. Then put in your new 3900.

I've put a full 8 pin in now. The existing 4 pin actually had 4 more (it was like an 8 pin but split) and the 4 that were already in place had CP on them, and the 4 extra have U1 on them. They are now in.

do some CPUs not need the full 8? as seems odd that the last one even worked with just the 4.

i've checked and my bios is version F7, and the latest it lists is F51b.

the scary thing is i'm struggling to follow the procedure in which i need to update first. it appears i can't update straight to the latest. but it's following the list of which order i odn't understand.

 

[unwashed potato!]

Edit removed

 

[unwashed potato!]

I've updated to f32.

Is anyone able to tell me which version I need to get to so that my cpu will be recognised?

https://www.gigabyte.com/Motherboard/GA-AB350-Gaming-3-rev-1x/support#support-dl

 

[Thekwango]

I've updated to f32.

Is anyone able to tell me which version I need to get to so that my cpu will be recognised?

https://www.gigabyte.com/Motherboard/GA-AB350-Gaming-3-rev-1x/support#support-dl

Bios versions for that board go from f31 to f40 so gonna assume a typo when you put f32. you need to be f40 min for 3rd gen Ryzen.

 

[VaderDSL]

F40 is the minimum version you need to support 3900X

 

[Thekwango]

Oh and make sure to run the firmware update tool first.

 

[Oh Ed not again.]

F40, looks like you've satisfied the intermediate step needed for the later releases too:

"Note: Before update BIOS to F40 or later version, make sure you have prior updated to F31."

 

[unwashed potato!]

Oh and make sure to run the firmware update tool first.

Run this from the bios or run this from windows?

 

[unwashed potato!]

F40, looks like you've satisfied the intermediate step needed for the later releases too:

"Note: Before update BIOS to F40 or later version, make sure you have prior updated to F31."

Once I get to f40, Is there any benefit to update further? Or should I stop there?

 

[Thekwango]

Run this from the bios or run this from windows?

Windows

scroll about half way down utilities downloads.

https://www.gigabyte.com/Motherboard/GA-AB350-Gaming-3-rev-1x/support#support-dl

 

[Thekwango]

Once I get to f40, Is there any benefit to update further? Or should I stop there?

There was some minor increased ram compatibility with further bios updates as far as I remember.

 

[unwashed potato!]

seems i've got it sorted now. thanks all.

maybe it's just me, but it seems my main screen is more vibrant now than before. the colours seem stronger.

wouldn't be related to the bios update?

 

[Oh Ed not again.]

Awesome.

Possibly placebo effect, but so long as it's a positive change, win.