Question PC powers up fine, but monitor keyboard and mouse not working

[AtomicPrime]

I just moved my PC to a new case, double checked everything and turned it on. Fans spin, my USB headset turns on, my USB expansion slot turns on, my motherboard led turns on, graphics card shows positive but the monitor doesn’t work, keyboard and mouse not working. It was all working perfectly fine before I fitted it in. I got no beep code and I didn’t touch my RAM or change my BIOS. All front panel connectors are in, SATA fitted in, GPU reseated but left with nothing but annoyance. Been at this for over 8 hours so any quick help would be great!

Motherboard: Asus Prime B250M-A
CPU: Intel I5-7400
16 GB of RAM
Radeon RX 580

 

[Lutfij]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. List them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:

Include the make and model of your PSU and it's age. Try and work without USB peripherals except for the keyboard and mouse.

Remove the CMOS battery and replace after 30 mins and see if your get any results with BIOS screen. The other thing you can do is breadboard the system with bare minimum(exclude the discrete GPU).

 

[AtomicPrime]

When posting a thread of troubleshooting nature, it's customary to include your full system's specs. List them like so:
CPU:
Motherboard:
Ram:
SSD/HDD:
GPU:
PSU:
Chassis:
OS:

Include the make and model of your PSU and it's age. Try and work without USB peripherals except for the keyboard and mouse.

Remove the CMOS battery and replace after 30 mins and see if your get any results with BIOS screen. The other thing you can do is breadboard the system with bare minimum(exclude the discrete GPU).

CPU: Intel I5 7400
Motherboard: Asus Prime B250M-A
Ram: Crucial 16GB DDR4
1 Seagate Barracuda 1TB hard drive
GPU: Radeon RX 580 8GB
PSU: Corsair CX 550
Chassis: Corsair Carbide Spec-Delta
OS: Windows 10

I have no idea how to remove the CMOS battery

 

[AtomicPrime]

CPU: Intel I5 7400
Motherboard: Asus Prime B250M-A
Ram: Crucial 16GB DDR4
1 Seagate Barracuda 1TB hard drive
GPU: Radeon RX 580 8GB
PSU: Corsair CX 550
Chassis: Corsair Carbide Spec-Delta
OS: Windows 10

I have no idea how to remove the CMOS battery

Update: Reset the CMOS battery but still not working. My PSU is about 8 months old and was still working perfectly before I changed the case