Turns off 5 min after start up. What is the easiest way to diagnose? Probably change power supply. ? Which one. Will this work with 20 y old ekectronics.
Clean the machine of dust. In particular, where is the processor and video card. Check how the cooler rotates on the graphics card chipset and on the processor. Measure the main power supply in the system unit. It's five and twelve volts.
Remove any dust from the device. Where are the video card and processor located specifically? Verify the rotation of the cooler on the processor and the graphics card chipset.