Question Black screen, computer running

[Hot___]

I have an Asrock h61m-hvs mobo and yesterday I updated the BIOS so I can use an i7-3770. The BIOS updated but I could not enter the windows, it keept giving me BSODs with the message "Inaccessible boot device". I tried doing some things but didn't work and after one restart it stopped giving signal to the monitor. I removed the GPU, connected the monitor to the mobo and removed the cmos battery but nothing.
Computer starts but the monitor shows nothing( the monitor led is flashing like the pc is off.

Edit: Removed the 4 pin pci e to see if it gives me any beep code or something, but nothing.

 

[helpstar]

reset the BIOS by jumper CLRCMOS1

after the BIOS update sometimes the boot priority is not set correctly in BIOS or AHCI is set to IDE by default or legacy BIOS/UEFI is switched

Which CPU is currently installed? Did you replace the CPU yet? check the CPU socket pins of the motherboard if some are bent or discolored

What 4 pin PCIe ? Did you mean the CPU ATX power plug? This has to be plugged, no matter what

 

[Hot___]

reset the BIOS by jumper CLRCMOS1

after the BIOS update sometimes the boot priority is not set correctly in BIOS or AHCI is set to IDE by default or legacy BIOS/UEFI is switched

Which CPU is currently installed? Did you replace the CPU yet? check the CPU socket pins of the motherboard if some are bent or discolored

What 4 pin PCIe ? Did you mean the CPU ATX power plug? This has to be plugged, no matter what

Yea my mistake with the 4 pin. I swapped the mobo and it does the same, tried with different psu, monitor and ram.
When it first happened i was using the i5 2400 and it still tdoes with both cpus