Dell Precision T3500 Black Screen and Red Lines

I recently installed an SSD into my T3500 and a fresh copy of Windows. I removed my old HDD in case I needed to use my PC again if I messed something up. Everything worked flawlessly and after a week I was normally uing my PC when my screen turned black and sound stopped. I turned it off from the power button and after 15 seconds turned it on. It goes to the "start Windows normally" screen but there are red lines and patterns and when I press enter it just stays black. My T3500 isn't making any sounds, no signal codes and the GPU fan is spinning. All cables are plugged in properly into both the PC and the monitor. I added my old HDD disconnecting the SSD and I went into BIOS and changed from AHCI to the option it was on before and rebooted but the same thing happened. When going into system repair it shows an image but the screen is full off red line (tried windows restore point but doesnt boot) . I tried removing the RAM sticks one by one however I get the same black screen after seeing the Windows logo screen. I don't understand why that happened and my suspicions are that the GPU is faulty but still has electrity passing through as the diagnostics code on the front of the PC do not light up. Has anyone had such a problem before and what was the issue? I doubt it's a DVI cable issue as it outputs image in Windows restore menu. Thanks in advance, I'm really panicking.