Question No HDMI Signal

[DacheZ]

Hello everyone,
So 2 days ago i tried to update my GPU's drivers (RX 560 2gb) everything went well, until i had to restart the PC to complete the update.
When it rebooted the screen was black, No HDMI Signal was written on the monitor.
I've tried to Change the input of the monitor, Hdmi 1/2 etc.
I've reset the monitor, cleaned the cables, tried a different one and nothing worked.
And I've removed all the RAM, cleaned the slots and placed them again.
So i removed the GPU and connected the HDMI Cable to the motherboard, and surprisingly it worked(The screen opened and everything works fine). So the monitor is not faulty.
I wanted to see if the GPU was faulty so i used an older GPU that i had lying around, and i got the same error.

Can you help me find out what i need to do in order for it to work?
Also some important notes, this had happened a few times when i tried to restart my PC, but it always opened after i restarted it 2-3 times.(This time i tried for 2 days and nothing changed).

Specs:
Mb: Dell XPS 8700
CPU: i7-4770
GPU: RX-560 2G
Ram: 16GB DDR3 1600hz I think
Stock PSU 460W I think.

Thank you so much!

 

[Lutfij]

Stock PSU 460W I think.
How old is the PSU? Did this unit come bundled with the Dell XPS prebuilt?

I wanted to see if the GPU was faulty so i used an older one that i had lying around, and i got the same error.
Specs to the donor system used to rule out your GPU being the culprit...?

 

[DacheZ]

Stock PSU 460W I think.
How old is the PSU? Did this unit come bundled with the Dell XPS prebuilt?

I wanted to see if the GPU was faulty so i used an older one that i had lying around, and i got the same error.
Specs to the donor system used to rule out your GPU being the culprit...?

This Pc was a gift from a long time ago, so from what i know its the stock PSU. On google it looks exactly the same if i search Dell Xps 8700 PSU.
The GPU that was laying around is a MSI ATI Radeon HD 4650, it came with the pc (Used it until i bought the RX560)

 

[DacheZ]

Stock PSU 460W I think.
How old is the PSU? Did this unit come bundled with the Dell XPS prebuilt?

I wanted to see if the GPU was faulty so i used an older one that i had lying around, and i got the same error.
Specs to the donor system used to rule out your GPU being the culprit...?

And I didn't try the GPU in a different PC, i tried an older gpu in the current one to see if i get the same error