Two PC's die in suspicious circumstances...

IggyStooge · 4 Jan 2020 at 18:09

Hello and Happy New Year to everyone,

Just before Christmas my main PC's PSU (Corsair RM650x) packed in, usual bang and slight flash. Fortunately I have a spare system which I set up without issue, used it a while and shut down. Came back to it and it wouldn't start and still won't. No sign of the Corsair CX430 PSU packing in. There is a blue light on the MOBO and I can hear a slight noise when I switch the PSU on. I did reset CMOS. What else can I try?

I'd started using a new Belkin six socket surge protector a few weeks before this all happened and I wondered if there could be a link. Is that likely? I've not used the surge protector since, opting for a new one when I bought a new PSU.

Thanks very much.

EsaT · 5 Jan 2020 at 09:24

Loud bang and flash is sign of high voltage/primary side failure/short circuit likely blowing up some power semiconductor.
That's one of the safer failure modes for PC components, because PSU's secondary is galvanically isolated from primary and just loses power shutting down PC.

That CX is standard cheap PSU and if its older/has seen more use its capacitors might be in bad shape, causing voltage regulation/ripple problems.
And light on mobo tells only that 5V standby is high enough to illuminate that LED, but not high enough to "turn it into smoke emitting diode".
Regardless of that voltage and ripple can be out of whack, preventing motherboard's circuitry from initiating power on process.

IggyStooge · 5 Jan 2020 at 09:36

Thanks EsaT. The CX is about 9 years old but has not had a large amount of use if that's of any relevance. Is it strange that two PSU's should encounter problems at the same time or just coincidence?

EsaT · 5 Jan 2020 at 09:50

Even without regular use 9 years is lots of years for cheap PSU.
Heck, actually little power on time once in a while would be good for longevity of capacitors by helping to maintain oxide layer in good condition.

If you're using spare system made from old parts also its BIOS battery could have run out of juice.
That can cause some illogical symptoms.
But that old cheap to start with PSU is definitely suspect.

Quartz · 5 Jan 2020 at 09:52

IggyStooge said:
I'd started using a new Belkin six socket surge protector a few weeks before this all happened

Get yourself an inline UPS that protects against brown-outs, power spikes, and so on. The inline is important as it means there's no switch-over time.

Smiffy-UK · 10 Jan 2020 at 19:49

Quartz said:
Get yourself an inline UPS that protects against brown-outs, power spikes, and so on. The inline is important as it means there's no switch-over time.

Thanks. Another thing I've learnt today that could help me. Just an observer

JasonM · 11 Jan 2020 at 03:45

IggyStooge said:
I'd started using a new Belkin six socket surge protector a few weeks

Belkin is poor quality, that surge protector probably has a $2 MOV in it.

A cheap way of doing surge protection is a mains RCD protector - that's correct the thing you plug the electric lawn mower into! So you have protection from inside the house, but also an external surge will trip them - even better they can't set fire like a surge protected power strip can.

And I know these work as external surge protectors, as a year previous we had a thunder storm, and it tripped, shutting down the equipment connected to it.

https://www.screwfix.com/p/masterplug-rcd-adaptor/63731

The power strip that is worth buying however is the Tacima HiFi mains filter, this does have a surge protector in it, but it also has noise filtering, and the filtering on these does 100% work.

https://www.youtube.com/watch?v=KGdJFLUgMl0

So to summarise. I use the Tacima mains filter, that's connected into an RCD mains protector. So I've got the best of both worlds, if there is a surge either external or internal the RCD will trip, and the Tacima is helping to filter the mains.

The other option is using an inline UPS as mentioned above, but I personally would want the UPS connected to it's own RCD as would not trust a UPS remaining on when I left the house.

Phil2008 · 11 Jan 2020 at 14:03

A UPS uses power as its constantly monitoring the mains power, a surge protector doesnt use power. So If you dont suffer from powercuts frequently, just get a well spec surge protector.

Edit: Whats a "Inline" UPS, I think you mean a "Online UPS".. These are more expensive then the normal "Line-Interactive" UPS because like Quarts says there's no switching from mains to battery power involved when the UPS detects somethings wrong... A Online UPS is always on battery power 24/7 and the mains power just keeps the batteries charged. Your plugged in devices receives constant steady power from the UPS's batteries 24/7 without any volts/hertz fluctuations.

UPS's do have there own breaker switch, so the UPS trips off if it detects a short circuit due to a faulty device thats plugged into it.

Phil2008 · 11 Jan 2020 at 15:34

Also dont knock unknown or not very well known brands, as 99% of stuff are manufactured in china now, because people want to produce things as cheap as possible.

I bought a PowerWalker 1800watt\2000VA online UPS for £350 and a well known brand like a APC UPS with the same spec would have cost me triple that to buy.

JasonM · 11 Jan 2020 at 16:17

Phil2008 said:
UPS's do have there own breaker switch, so the UPS trips off if it detects a short circuit due to a faulty device thats plugged into it.

I was not aware of this, I presume that's something included in all good UPS's.

Do UPS's also have a breaker if the internal battery, or the unit itself started to short out?

Phil2008 · 11 Jan 2020 at 16:52

My belkin ups had a breaker switch that lasted me near enough 10yrs.

I dont think UPS's has a breaker switch for the batteries, but my UPS warns me if its not working correctly, and I guess it will power off if anything is seriously wrong.