I'm new to building and troubleshooting computers, so I'm not sure where to start. My system has a GeForce RTX 4070, a Helios P1 650W power supply, 32GB of Corsair RAM, an M.2 SSD, and a Biostar motherboard. I don't know the CPU model.
While I was playing a game, the computer suddenly powered off. It wasn't a household power outage because another computer in the home kept running. Since then, only the RAM lighting turns on. The case fans, GPU fans, internal lighting, and the rest of the system do not appear to receive power. My keyboard, mouse, and the computer's power button still seem to have power.
I tried holding the power button down, removing the GPU, disconnecting other devices, and using a different wall outlet in another room. None of that helped. The motherboard also shows no diagnostic LED lights when I press the power button. The only recent change was installing the RAM about a month ago.
Does this sound like a failed power supply, or could the motherboard or another component be causing the problem?
2 Answers
The power supply is a reasonable first suspect, especially since the system shut off during a game and now won’t start at all. Try a known-good replacement PSU with enough wattage for the RTX 4070. If the replacement is modular, use only the cables that came with that PSU—never mix modular cables between power supplies, even if the plugs fit. Also make sure the 24-pin motherboard cable and CPU power cable are firmly connected.
Check the motherboard for any standby or diagnostic LEDs, but no lights doesn’t automatically prove the board is dead. Before replacing parts, disconnect all USB devices and drives, reseat the RAM, and try starting with one memory stick installed in the recommended slot. You can also briefly test the power-switch pins with a screwdriver to rule out a faulty case button.
There aren’t any motherboard warning lights when I press the power button. I’ll try reseating the RAM and checking the power connections.
That makes sense. I’ll try a different power supply and make sure I use its own cables.