Question Power Supply making faint rattling noise when PC turned off but still plugged in!

[Dave3000]

I recently purchased a refurbished Dell Optiplex 5050 SFF desktop PC and I noticed that in a quiet room if I put my ear about 1 foot or closer from the PC, I can hear a faint rattling noise when the PC is turned off. I opened up the PC and tried to pinpoint where exactly the rattling sound was coming from while the PC was plugged in but turned off and it was come from the front part of the power supply, but the fan was not spinning, and therefore it was not power supply's fan but still coming from the power supply. To exactly describe the sound it sounds like those vintage film reel machines when the are playing films on the projector but quieter. It's a very old PC as it came with an i5-6500 CPU but I got a good deal on it. Is this normal for this PC? My main desktop PC does not have this issue. I'm still within the RMA period.

 

[mindless1]

Can you record this noise and post to youtube or wherever?

If it's not the fan then it seems like it might be arcing of some component, possibly in the AC filter stage or the 5VSB subcircuit.

If you don't feel comfortable DIY repairing it then yeah, time to RMA it.

 

[Dave3000]

It's like a quite quick ticking signature to the sound, not fast enough rate to be a constant hum, but slow enough rate to have tickiness to the sound, like maybe at a rate of 30-40 ticks a second. Anyways I returned the system as I was still within the return period.