I'm troubleshooting an older PC that shows no signs of starting: the fans do not spin and it does not appear to reach POST. I've already tried reconnecting most components, using different motherboard pins, reseating the RAM, and following several troubleshooting suggestions. The system uses an ASUS P8H61-M PRO motherboard, an Intel i5-2400, 2 GB of DDR3 memory, and a 450 W power supply. The motherboard's green standby light is illuminated. What should I test next, and which component is most likely to have failed?
3 Answers
Since this is an older platform, a failed component is very possible. With absolutely no fan spin, the PSU, case power button, motherboard, or CPU power connection is more likely than the RAM. Disconnect everything except the motherboard, CPU with cooler, one memory stick, and PSU, then test outside the case if necessary to rule out a short.
A motherboard standby light only confirms that some 5V standby power is reaching the board; it does not prove that the PSU can start the system. Check that the 24-pin motherboard connector and the 4-pin CPU power connector are firmly attached, verify the PSU switch and wall connection, and try starting it by briefly shorting the two power-switch header pins with a screwdriver. If there is still no fan movement, testing with a known-good PSU would be the next step.
The green light means the board is receiving standby power, but it does not confirm that the main power rails are working. If the PSU passes a proper test or a replacement PSU behaves the same way, inspect the front-panel header and try the minimal setup. At that point, the motherboard itself may have failed, especially given the system’s age.
I think the PSU is connected correctly because the motherboard’s green light comes on, but I’ll recheck the CPU power connector and test the power-switch pins.