My older PC suddenly started powering on for about a second and then shutting off without ever reaching POST. I tested it with the motherboard removed from the case and only the CPU installed, but the behavior was the same. A paper-clip test makes the power supply fan and unit run, so I initially suspected the motherboard or CPU. However, after reassembling everything, the system unexpectedly booted and ran games normally for several hours before returning to the same power-cycle problem the next morning. The power supply is roughly 12 years old, so I'm now wondering whether it can still be the cause despite passing the basic jumper test. I'd like to reuse my recently purchased graphics card and preferably some other existing parts, including 24 GB of DDR3 if possible. My games include PUBG, Elite Dangerous, and lighter PC titles. I'm in the United States and would prefer to stay well below $1,000, although I could stretch to that if necessary. I'm hoping for a reliable replacement that can last several years rather than an extravagant build.
4 Answers
I’d troubleshoot in this order: install a known-good PSU, clear CMOS, boot with one memory stick, and disconnect every unnecessary drive and USB device. Check that the CPU power connector is firmly seated and inspect the motherboard for shorts or damaged components. If it still immediately shuts off with a known-good PSU and minimal hardware, then the motherboard becomes the leading suspect. The CPU is the least likely part to have failed.
A new PSU is worthwhile even if the motherboard turns out to be bad. Just make sure the model has enough PCIe power connectors and adequate wattage for your GPU, and use only the modular cables supplied with that PSU. Don’t reuse modular cables from the old unit, since the pinouts may differ.
Your existing DDR3 memory will not work with current platforms, and it probably isn’t worth choosing a new motherboard just to keep it. If the PSU replacement doesn’t solve the issue, a used AM4 system or a reasonably priced LGA1700 platform could let you reuse the newer GPU while replacing the old motherboard, CPU, and memory. You don’t need a high-end processor for the games you listed.
A paper-clip test only shows that the PSU can turn on with no real load; it does not prove that the voltages remain stable when the system tries to start. Given that the unit is about 12 years old, the PSU is the first thing I’d replace. Intermittent power-on and shutdown behavior fits an aging PSU much better than a failed CPU. A new 750W Gold-rated unit should be a reasonable choice and could be carried into a future build, assuming it has the right connectors for your graphics card.
That makes sense. It has been a great workhorse, but replacing the PSU first seems safer than buying a motherboard and CPU without knowing the real problem.