Corsair PSU popped and sparked

[JG234]

My PSU is the Corsair HX620.

Just a few moments ago I turned my PC on, as I did so there was a loud pop and a blue spark
was thrown out from the PSU. It fell through the fan grill and dissapeared into my acrylic side window.
There was NO smell of burning and there was NO smoke. The PSU not dead, but I am a bit worried about it TBH.

This has happened a few times over the last few months - quite rare actually. It's like some kind of power surge.
I don't think the PSU is to blame but more how my cables/plugs are set up. Here's a little diagram to help me explain the situation:

I have a Belkin Surgemaster, plugged directly into the wall. My PSU's power cable is connected to this. The PSU's kettle plug is connected all the time, I never remove it.

First I switch the wall socket switch on, then I flick the PSU's switch. Finally I flick the Surgemaster's switch to bridge the two. THIS is when the PSU pops/sparks.

Should I switch on the PSU last?
Is the Corsair on its way out, or this is normal/not harmful?
Where is the spark coming from?
Has this happened to anyone else?

Any help/advice would be much appreciated.

 

[JG234]

OK, thank you everyone so far.

I have just started the RMA process, but that will probably take a while to go through - in the meantime what replacement PSU should I buy?

Another Corsair? I am hoping mine is just a one-off.

Strange to think I bought this PSU because I was worried about my 580W Hiper failing...

 

[JG234]

Just that I leave the surgemaster & psu switch permanently on and just turn the wall on/off.

I tried that just now, there was no pop or spark. Still, I think there's something seriously wrong with the PSU so I ordered a HX520 from Overclockers.

dont you have to send it to the USA?

Yes, apparently. It will cost loads, probably half what the PSU is worth. I may not bother sending it back, I will see what the 'RAM GUY' says first...

Thank you everyone!

Nice picture though.