Why does new PSU make LED bulb flicker so much ??

[MathWizard]

I had an old 850W PSU, and there's about a 14W LED bulb plugged in, on the same circuit as my PC and stereo. It never really flickered before.

But then I got a new Super Flower Leadex 1200W 80+ Platinum PSU, and as soon as the PC is running, the bulb flickers. On a 3.5D DMM, the voltage goes from about 117.3VAC to about 116.3VAC, when the PC is on. It moves up/down a bit, with the PC on or off though.

The flickering is more like a few times a sec/ or not much faster. It's fairly annoying, I'll try some other bulbs. I guess there's not much else I can do, these bulbs are too hard to take apart anyways.

So is it bad light bulb design or bad PSU design? How much sub 60Hz noise is allowed ? I'm tempted to drag the scope over had have a look.

Geez these are safety plugs tho, it was a pain to get DMM probes in the slots, and to find contact.

[thm_w]

Is it a quality brand LED bulb?

Interesting that it got worse, you'd think the high quality PSU would have good PFC and not cause large draw. But, did you just change the PSU or does your PC now draw a lot of power too?

[MathWizard]

No it's the same PC, and happens when idling, and together with the stereo, they probably use under 150W. I never paid attention to the light when I was gaming, but those games don't use that much power either, (my PSU is overkill, but not at the great price I got it, and it's for an i9-14000KF and RX 7900 xtx)

The bulb is a non-dimmable 8.5W type, not a big brand name but from a big supermarket, so legit. Of the couple I tried, they both flicker. I tried a working Sylvania 13W compact florescent, it flickers a bit, but not nearly as bad as those LED's. I wonder how bad an incandescent bulb would be. I still want to check the voltage with my scope too.

[macboy]

Smells like badly designed PFC in that new PC power supply.