No video, No USB

[x360720x]

Hi all,
 

Took my whole PC apart today to try and increase airflow - switched on successfully, was able to login etc, when I restarted it the following appeared "A required device isn't connected". After a bit of googling it was recommended to remove the CMOS battery and try again - now I have no video signal nor the USB ports work (All fans, lights etc are working). Any ideas?

Specs:
AMD Ryzen 5 2600
DarkRock Pro 4
Gigabyte AB350M
8gb Kingston Fury DDR4 
Palit GTX660 3gb
OCZ Fatality 550w

[WereCatf]

Did you flip the switch or remove the cable from the power-supply before removing the CMOS-battery? Or even worse, did you remove the CMOS-battery while the system was running?

[x360720x]

PSU was switched off and power cable was removed

[WereCatf]

Are you sure the CMOS-battery is fully seated in its socket and making proper contact with the metal tabs?

[x360720x]

Yeah 100% sure. Do you know if removing the battery rolls back BIOS updates? (I did have to send mine back to Gigabyte when I originally bought the motherboard as the CPU was not yet compatible without the update)

[WereCatf]

2 minutes ago, x360720x said:

Yeah 100% sure. Do you know if removing the battery rolls back BIOS updates? (I did have to send mine back to Gigabyte when I originally bought the motherboard as the CPU was not yet compatible without the update)

No, the BIOS is written in a small flash-chip on the motherboard and the flash-chip keeps its contents, even if the CMOS-battery broke or went empty.