New build system causing room lights to flicker

ik9000 · 25 Feb 2020 at 13:48

Ok folks, I've got a weird one here: Built new system over the w/e. Powered it on last night. Everything works. But...

when you first start it up something makes a weird sound (ends after 30s or so) and all the lights in the room start to flicker, like disco-strobe (they are LED dimmer bulbs). Once the machine is running everything is fine. A restart doesn't cause the issue, just cold-start from powered off. WTF is happening?

Is it a case of too little load on the PSU? Do I need to throw some old HDD in there to boost the start-up load? Is it interference from the surge protector? I'm loathe to plug it in without the SP as 1) it is the extension cable to get power to the desk, and 2) it just feels unwise, I've never run my desktop without one - and I've seen other people have screens go pop due to bad rentals etc.

House is newly wired in the last 12months to modern regs with MCBOs on the mainboard etc. Lights and plugs do not share a circuit at all.

PSU is a brand new Seasonic Snowsilent Titanium Prime Ultra 750w SST-750TR. I paid good money to try and avoid this kind of crazy. Typical! :rolleyes:

Grimley · 25 Feb 2020 at 14:45

Have you plugged in the PC somewhere else in the house? Is it plugged into the mains directly or via a surge protector?

ik9000 · 25 Feb 2020 at 17:21

Surge protector but have used it for years without issue. I'll try without that too this evening just to make sure

ik9000 · 2 Mar 2020 at 13:01

Removed the surge protector and it's been fine; no issues

EsaT · 2 Mar 2020 at 20:48

Components of that surge protector have likely worn down and wouldn't do anymore much to protect PC from any surges.

ik9000 · 2 Mar 2020 at 20:59

Yeah wouldn't surprise me. I'll stick it in the office PAT test cycle and see what they make of it!

wolfie138 · 3 Mar 2020 at 09:02

I've had a looooong ongoing flickery light problem [due to the powergrid suppliers] that was only resolved in Jan. all my house lights are LEDs and apparently they're a lot more susceptible to current issues; flickery is caused by drops rather than spikes apparently. high drain appliances can sometimes cause a just-noticeable blink when eg a kettle is switching on/off - could it be your surgeprotector/PSU is overdrawing/over-compensating and putting a bigger drain on your house wiring? sounds like the SP from the above.