Question PC blackscreen after reinstalling the old CPU to update the BIOS ?

[TheHelpRequirer]

My gaming PC failed to boot up after CPU upgrade... I then remembered i had to update bios so I reinstalled my old CPU to do the bios update.
And now the PC is on a black screen
Sometimes it loads and i can load up bios but it goes back to a blackscreen afterwards.
Its a rare chance bios will load up.


Things i've tried:

• Restarting bios with the KTS battery
• Changed storage systems
• Replugging the old cpu 4 times
• Plugged in keyboard & mouse

Things that are working:
The keyboard & mouse lights up
All the coolers still work


Things that dont work:
The screen on the monitor stays black after unplugging (assuming no signal is getting sent to the monitor) i doubt the hdmi is the issue
But i could be wrong

The case did blink red after exiting bios
Either way could someone identify the issue so i could possibly take it to a repair shop if the issue is too big?

Specs:
AMD Ryzen 3 1200 (tried to upgrade to a Ryzen 5 4500)
Radeon RX 550
MSI A320M-A PRO (hdd covering the rest)
Windows 10

 

[helpstar]

install the old CPU
reset the BIOS by jumper JBAT1 (page 14 in the manual: https://download.msi.com/archive/mnu_exe/mb/M7C51v1.0.pdf)

verify which BIOS version is flashed (get into BIOS to have a look)
update with version 7C51v18

View: https://www.youtube.com/watch?v=sKMub20CUNI

A320M-A PRO | Motherboard | MSI Global

Best AMD AM4 A320 Micro ATX motherboard, USB 3.2 Gen 1, MSI PRO

www.msi.com

Is the cpu fan plugged in?

Did you plug in the hdmi into the RX550 and not the motherboard?

Are all power cables still in place?

use minimum setup:
motherboard, only one RAM, CPU with fan, PSU, RX550, keyboard, monitor

 

[TheHelpRequirer]

install the old CPU
reset the BIOS by jumper JBAT1 (page 14 in the manual: https://download.msi.com/archive/mnu_exe/mb/M7C51v1.0.pdf)

verify which BIOS version is flashed (get into BIOS to have a look)
update with version 7C51v18

View: https://www.youtube.com/watch?v=sKMub20CUNI

A320M-A PRO | Motherboard | MSI Global

Best AMD AM4 A320 Micro ATX motherboard, USB 3.2 Gen 1, MSI PRO

www.msi.com

Is the cpu fan plugged in?

Did you plug in the hdmi into the RX550 and not the motherboard?

Are all power cables still in place?

use minimum setup:
motherboard, only one RAM, CPU with fan, PSU, RX550, keyboard, monitor

I had the old cpu installed
The HDMI is always in the rx550
If i try to connect it to the motherboard its a blackscreen
Its been like that for years
The cpu fan is a must have if i want to boot up my pc
I didnt touch any power cables in fear i might fry something
I was able to run bios again but when i exitted the screen went to a blackscreen and the case started blinking red
I think... i corrupted my hdd
But either way i can replace those easily
I already backed up most things off of it
The minimum setup gives the same outcome.(currently trying to find my way back to bios so i could possibly update my bios)


Status update 2:now the case is just blinking red after starting up
Wasnt happening before removing and reapplying the gpu


Status update 3:I removed the old cpu to see if the issue was the cpu or not and the screen shows the same even with the cpu not placed in
I think my motherboard is failing to detect the cpu causing it to not boot up
And if it does it runs a screen saying something about my old cpu and says enter setup (bios) but its a small chance to get that screen again. which i had no luck of getting back into within the time i originally made this reply. Also the red blinking with the gpu stopped