My PC stopped turning on after my phone charger briefly contacted the audio jack. Disconnecting the front-panel HD Audio cable let the system start again, but afterward I had to unplug the power supply and hold the case power button to discharge it before the PC would turn on. Swapping in an older PSU fixed the problem, so the original power supply appears to be faulty. It's an MSI MPG unit that's about five years old. Is PSU repair practical, or would it be safer and more cost-effective to replace it?
4 Answers
For most people, replacing a questionable PSU is the right move. An unreliable power supply can damage other hardware, and quality replacement units are affordable enough that repair costs and risk usually aren’t worthwhile. Stop using the faulty unit rather than repeatedly unplugging it and trying to make it start.
Before buying anything, check the warranty. Many MSI MPG power supplies carry warranties around 7–10 years, so a five-year-old unit may still qualify for a replacement. Contact MSI with the exact model and proof of purchase instead of opening it yourself.
If the problem is only a modular cable or fan, repair can sometimes be possible, but internal PSU faults are a different story. Unless the manufacturer handles it under warranty, replacing the unit is generally safer than troubleshooting it yourself.
Don’t open or attempt to repair a faulty PSU unless you have professional experience. The capacitors can retain dangerous charges, and diagnosing the failure may require specialized test equipment and careful soldering. A mistake could create a fire hazard or damage every component in the computer.

I completely forgot to check the warranty. I’ll contact MSI first rather than trying to repair it.