My RGB setup was causing random shutdowns until I realized the power draw was exceeding my PSU's 12V rail capacity

I figured it out by using a multimeter to test the voltage under load, which revealed significant sag on the 12V rail.

6 comments

6 Comments

Yikes, that's a classic PSU overload scenario. From my experience, RGB lighting can draw surprising power from the 12V rail. Testing under load with a multimeter is the right move to catch that.

the_seth3h ago

Man, your comment about RGB reminds me of my buddy's build last year. He had a solid 650W unit, but six of those fancy ARGB fans dropped his 12V rail to 11.4 under a gaming load, just like @craig.pat mentioned. Total instability until he swapped the PSU.

simon1683h ago

Hold on, I've run plenty of RGB-loaded systems on budget power supplies without any voltage sag. Those little LEDs draw peanuts compared to a hungry GPU or CPU under load. People jump to blame the lights when it's usually just a crap PSU or daisy-chained fan headers causing the problem.

allen.cora1h ago

Isn't it possible that those LED peanuts add up when you've got a dozen fans lit up? @craig.pat's multimeter tests usually point to the RGB as a culprit in unstable systems.

gavinmurphy1h ago

Didn't we all assume LEDs were just cosmetic until they crashed a system? I've been down that road, and craig.pat's multimeter tests are spot on. My last build had a dozen addressable fans, and under load, the 12V rail dipped to 11.3 volts, causing random resets. Took me weeks to diagnose because I blamed everything but the lights. Swapping to a higher wattage PSU fixed it, but the lesson was clear: those peanuts add up. Now I always budget extra headroom for RGB, no matter how trivial it seems.

wadek553h ago

Notice how this debate keeps popping up in every PC building forum? It reflects a bigger issue where people prioritize visible aesthetics over system stability, often ignoring critical components like the power supply. As craig.pat mentioned, testing under load with a multimeter exposes the truth, but how many builders actually take that step? We're in an era where flashy RGB distracts from the fundamentals, leading to the same preventable failures. Isn't it ironic that we spend hundreds on lighting but cheap out on the part that keeps everything running? This pattern repeats because we're sold on the sizzle, not the steak, and it's time to shift focus back to engineering.