I'm a complete beginner and I'm running out of ideas before taking my computer to a repair shop. My old power supply seemed faulty after failing a paperclip test and making an unusual noise, so I replaced it. However, the computer still won't start.
The 24-pin motherboard connector and 8-pin CPU connector are secured, all other cables appear connected, and I've reseated the RAM several times. I also tried clearing CMOS, replacing the case power switch, and testing the new power supply with a paperclip; the PSU fan and other components spin during that test. The motherboard's standby LEDs are lit, and the PSU switch is definitely set to on, but pressing the power button does absolutely nothing. What should I check next?
4 Answers
Double-check every cable by unplugging and firmly reconnecting it, especially the front-panel power-switch connector. You can also use the motherboard manual to identify the power-switch pins and briefly short those two pins with a screwdriver. If the system starts that way, the case switch or its wiring is the issue.
Since the new PSU passes the paperclip test, make sure it has enough wattage for the system and some extra capacity. Also verify that the PSU’s 24-pin and CPU 8-pin cables are connected to the correct sockets. A paperclip test only shows that the PSU can turn on; it doesn’t prove it works properly under load.
Try booting with only one RAM stick installed, testing each stick separately and using the recommended slot from the motherboard manual. It’s worth checking, although faulty RAM usually allows the system to power on and then produces no display or a diagnostic beep rather than causing absolutely no response.
If the motherboard has standby power but none of the fans or indicators react when the start pins are shorted, the original PSU may have damaged the motherboard or another component. Testing outside the case with only the motherboard, CPU, one RAM stick, and PSU can help rule out a case short or an extra connected device.
The power supply is on and the standby LEDs are lit, but I’ll try starting it directly from the motherboard pins.