Resposta para "Turns off in a few seconds after turned on."Overheating problem. Worth a stripdown and reapply the heat sink compound to the CPU / heatsink.
Resposta para "ceramic fuse is blowing in power supply board"Check for short after fuse. Voltage dependent device (if fitted, a blue flat disc size of 1p coin) will go short, as can the bridge rectifier or the smoothing capacitors.