Question Monitor suddenly goes black then NO SIGNAL but keyboard and mouse stay on

[MAHNIIII230]

I have a second-hand computer set. I recently changed the HDD to SSD. The problem starts that my computer boots up very slowly. When I use it, for about 1 hour or 2 hours it proceeds to go black then the NO SIGNAL message but my keyboard and mouse remain on (their lights are still on). When I restart it or hard shut down then turn it back on, it will now repeatedly go back to the scenario. Connecting my LAN cable also won't work that is why I use a wifi adapter to make it wireless. I don't know if it is the GPU or motherboard or CPU. There is also this issue that no matter how I balance or level my audio the right side is always lower than the left side. No matter how I adjust it.

Specifications:

Processor: AMD Athlon(tm) X4 740 Quad Core Processor 3.20 Hz
Installed RAM: 8.00 GB
Power Supply: Brand: CVS Model: P4-700W
Motherboard: EMAXX FM2
GPU: MSI N1996 model: V279 Radeon R7730-2GD5 S/N 602-V279
SSD: Ramsta SSD 256GB

 

[rgd1101]

brand and model of this atx 700w? could be failing

 

[DSzymborski]

The information you gave for the GPU does not correspond to any GPUs.

 

[MAHNIIII230]

brand and model of this atx 700w? could be failing

Brand: CVS
Model: P4-700W

 

[MAHNIIII230]

The information you gave for the GPU does not correspond to any GPUs.

MSI N1996 model: V279 Radeon R7730-2GD5
S/N 602-V279

I think that is the information about my GPU