Yeah, the issue is its not doing anything at all.
As I said as soon as you mentioned swapping PSU from another case -- your brother should have returned all of it and asked for a full refund and he should have gone to another store.
He figured the PSU they swapped for him would work, I mean what are the odds? And the store told him they checked the machine and that it WAS the PSU. At that stage perhaps it was. They are an IT store, why wouldn't you take their word for it? Your computer isnt working, you take it to the store, they tell you its the PSU and they'll replace it... you are happy right? One would assume they know what they are doing.
Anyway when the second one blew up he
did ask about getting a refund on the whole thing, since it was bought as a case/psu combo. The manager who speaks bad english at Ultimo said no. He kept flouting their rule about no refunds after 7 days from the 'invocie' as he so eloquently put it.
This was despite the fact that 5 of those 7 days were actually wasted by MSY themselves supposedly checking the machine for damage.
It was only after my brother got sick of everything and got really angry with them that the guy told him he could get the refund.
He then went to another store entirely and ordered the silverstone psu and different case.
I seriously doubt the silverstone bought from a different store is screwed.
Which is why im guessing that when msy were supposed to check the components for my brother, they actually didn't because they were too busy and couldn't be buggered. Or they didn't know what the hell they were doing and just assumed it was the PSU again, when it was the mainboard all along and the second PSU wouldn't have even blown up if they'd done their jobs properly. Thats my humble opinion anyway.