Big spark just from PSU plug!

katie279 · 27 Sep 2021 at 11:00

Hi all,

Never had this before, so keen to get some advice and suspicion of causes before I start fiddling.

Was just working on my PC when it suddenly cut out on a zoom call - assumed there was a power cut or something, but realised it was just my pc that had cut out.

I could see the RAM was still illuminated etc inside, so obviously some current still coming to the MB, so tried checking all the plugs were connected fully - all looked fine.

Unplugged the PSU three pin plug in the back of the PC and plugged it back in to doublecheck and got a visible large spark at the back of the PC and a loud pop and tripped electricity on this floor of the house.

Scratching my head as to what could actually cause this - strongly suspect I'll need a new PSU (was a be quiet! Pure Power 11 500W 80 Plus Gold Modular Power Supply).

Has anyone else had something like this occur before and any advice!

VersionMonkey · 27 Sep 2021 at 11:20

If the cable is plugged in/switched on at the wall it is ~~not~~ usual to get a small spark when inserting the plug into the back of the PC. Making sure the switch on the back of the PSU (if it has one) is off is usually sufficient to stop this; although it seems that bequiet are unusual in that the switch doesn't completely isolate the power and the PSU will continue to supply standby voltage even with the switch in the off position - so it's likely you'll always get something if you connect the plug to the PSU while the other end is plugged in at the wall.

On the other hand, it is very unusual for that small spark to trip anything and it's possible that you do indeed have a faulty PSU, or a short somewhere else in your system. Do you know if it was the RCD/earth leakage that tripped (which would probably have taken out other circuits as well), or just the breaker for the power sockets?

Ideally you could do with taking the PSU out of the PC and testing it seperately.

Edit: I probably meant to type "not unusual" in the first sentence.

katie279 · 27 Sep 2021 at 11:37

Hi there, yes it was quite a load pop and a large spark - not the usual one you mention.

It was just the breaker for the sockets that went - might have a look later, just don't want to damage any other components!

VersionMonkey · 27 Sep 2021 at 12:08

katie279 said:
It was just the breaker for the sockets that went - might have a look later, just don't want to damage any other components!

It can be a bit tricky getting the connectors off the motherboard, but testing the PSU outside of the case is likely to be the best way of preventing any further damage (assuming that's what is faulty).

katie279 · 27 Sep 2021 at 13:04

Yeah fine - only built the PC 12 months ago or so, so shouldn't be too much effort to remove. Think I might order replacement PSU anyway and drop that in and can load test the PSU on a test rig for a bit.

I suspect it'll either be totally dead or it'll be an annoyingly intermittent issue as PC was obviously running fine for months before, so might be hard to replicate....

EsaT · 27 Sep 2021 at 15:33

Especially if you didn't power PSU off from rear switch primary capacitor got emptied.
And NTC thermistor which normally limits inrush surge when connecting PSU back to power was propably still warm.
So if you connected PSU back to wall without letting it cool, it's possible that thermistor simply didn't do much any to limit current draw of capacitor charging.
(unrestricted big capacitor charging starts from near short circuit situation)

As for original shut down issue that PSU isn't exactly any highest qualtiy one, but mid level one with second tier parts.
So if it's older/has seen lots of use it's possible that it might be starting to show age.

katie279 · 1 Oct 2021 at 21:41

Great summary Esat, this makes a lot of sense.

PSU was recommended in this forum 12 months ago, hence I bought - you got any recommendations for a replacement?

These seem to be well rated?
https://www.overclockers.co.uk/seas...-titanium-modular-power-supply-ca-077-ss.html

mickyflinn · 1 Oct 2021 at 22:14

I would get corssir rm 650w for £70 on Overclockers 750w is £80 if you want more headroom. 10 year warranty fully modular.

https://store.overclockers.co.uk/pc-components/power-supplies/up-to-800-watts?page=2&sort=price_asc

katie279 · 1 Oct 2021 at 22:53

Thanks! Could you ping links? I can't see an overclockers 750W modular one, only a fairly basic looking ocuk one. Might be the new site or me!!!

Grimley · 2 Oct 2021 at 07:52

Price on the Corsair has gone back up - Alternative:

My basket at Overclockers UK:

1 x Phanteks AMP 550W 80 Plus Gold Modular Power Supply= £72.95

Total: £83.45 (includes shipping: £10.50)

EsaT · 2 Oct 2021 at 09:22

katie279 said:
Great summary Esat, this makes a lot of sense.

PSU was recommended in this forum 12 months ago, hence I bought - you got any recommendations for a replacement?

These seem to be well rated?
https://www.overclockers.co.uk/seas...-titanium-modular-power-supply-ca-077-ss.html

BeQuiet's brand hype sells, while in fact they've had very little actually high quality level PSUs.
And have had very substandard warranty lengths per price...

Seasonic Prime Titanium belongs to absolute top PSUs.
(unlike Silverstone Strider Titanium designed for checking that efficiency in marketing)
Though you're paying luxury for that performance and super high efficiency at all operating loads.

What PC parts you have?
That decides what size PSU is needed.
Though if 500W one worked without constantly tripping over 650W PSU certainly does it.

katie279 · 2 Oct 2021 at 17:22

Sorry all, just opened up rather than looking at my overclockers shopping orders and realised I forgot there was another PC I built...

This one has a Phanteks PSU, so build is:

- AMD Ryzen 3600x

- Phanteks AMP 650W 80 Plus Gold Modular Power Supply

- Gigabyte GeForce RTX 2060 SUPER WindForce OC 8192MB

- 32Gb Ram
- Phanteks Eclipse P400S Glass Midi Tower Case - Noise Dampened White

- Gigabyte 1TB M.2 PCIe x4 NVMe SSD/Solid State Drive

- 1gb Samsung ssd

I've tried plugging it back in, but it's tripping the electricity every time I turn the PC power on. This likely to be the PSU or could it be something internal?

Also is the Phanteks PSU worth replacing??

katie279 · 2 Oct 2021 at 17:34

Have also just tried with different kettle cords, so same occurring and also just move the base unit to the garage and tried there, same thing (loud bang, spark at the back and electricity tripped)

So definitely something odd with the PSU or something within the PC. Given the spark is coming out the back of the PSU, could this be anything other than the power supply (eg if I was shorting something inside the case, I'd assume it'd not spark at the back of the PSU??)

If so, think I just need to RMA and order a new one...!

VersionMonkey · 2 Oct 2021 at 19:24

I would say that is pretty certain it's a short in the PSU. If you want to be completely certain, take it out of the PC (you are going to have to anyway to RMA it) and plug it in by itself.

Grimley · 3 Oct 2021 at 06:50

Your Phanteks PSU should have a 10 year warranty, so they should replace it if it is confirmed to be faulty.

EsaT · 3 Oct 2021 at 09:21

katie279 said:
So definitely something odd with the PSU or something within the PC. Given the spark is coming out the back of the PSU, could this be anything other than the power supply (eg if I was shorting something inside the case, I'd assume it'd not spark at the back of the PSU??)

If there's spark inside PSU and not in connector when plugging in cable there's something broken/faulty there.

Phil2008 · 8 Oct 2021 at 03:09

I had a few spark and go pop on me when the psu comes to the end of their life... Its totally normal, plus it saves the rest of your hardware going pop,, so its a good thing.