PC won't turn on - no display, no beeps

You press the power button. Fans spin. Lights come on. But the monitor stays black and there are no beeps. Before assuming the worst, work through these checks in order.

1. Check the monitor and cable first

Sounds obvious, but try a different display cable, a different port on the GPU, and confirm the monitor is on the right input. If your CPU has integrated graphics, try plugging into the motherboard's display output instead of the GPU - this isolates whether the GPU is the issue.

2. Re-seat the RAM

The single most common cause of a no-display, no-beep boot is loose or misaligned RAM. Power off, unplug, remove each stick, and push them firmly back in until both clips snap. Try with one stick at a time in the slot nearest the CPU.

3. Re-seat the GPU

If you have a dedicated GPU, take it out and put it back in, making sure the PCIe lock clicks and all power cables (if it needs more than one) are connected.

4. Listen for the PSU

Unplug everything except the 24-pin and the CPU 8-pin power. Briefly jumper the green and any black pin on the 24-pin connector with a paperclip - if the PSU fan doesn't spin, the power supply is dead.

5. Look at the motherboard

Most modern boards have debug LEDs (CPU / DRAM / VGA / BOOT). Whichever one stays lit tells you exactly which subsystem is failing. No debug LEDs? Look for a small post-code display.

When to stop and send it in

If you've done all of the above and still have nothing, you're likely looking at a dead motherboard, dead PSU, or a CPU that's lost contact with the socket. Component-level diagnosis on the bench can pinpoint which - and often fix it without replacing the whole board.