New HX650 loud grinding and electrical sounds on startup

Hello

My new HX650 is making worrying sounds. It installed fine, and I double checked all connectors were inserted correctly, cables not hiting any fans etc and started up computer - everything fine.

I left the computer off and unplugged from mains for around 12 hours. When it was powered back on the psu made a loud motor engine sound, like an idling car. I switched off right away in fear of psu faliure, unplugged from wall, and checked psu - no smoke/smells/burns, power cable correctly inserted etc.

I looked online and found this forum, and I read through it until I found this thread of someone with the same problem, they had posted a youtube video of the noise: http://www.youtube.com/watch?v=_uRpWQwJ8Dc

It is identical to the noise my psu makes on startup.

Left it off for 24 hours whilst I contacted the seller of the HX650, who did not respond. It seems they might not take it back and replace it until it actually fails.

Tried to start up the computer again just an hour ago, and as I turned it on at the plug, an extremely loud electrical 'crack' sound occured inside the computer, I do not know where from but it sounded around the psu/mobo area. The computer started up okay, but the psu is still making the loud motor sound. I left it on for a while and the motor noise died away eventually, but it took around 10 mins.

It would seem the loud engine sound is the fan, but the electrical crack worries me. Is it okay to continue to use the computer, or do I need to replace the psu? I live in the UK and need my computer to hit a deadline this January (I am a digital animator) so I am in quite a panic about any downtime this causes and potential system/data loss if I keep using it. If my seller won't offer a replacement (I will be telephoning them tomorrow and trying to get one), is there anything I can do?

Thankyou very much for any suggestions!