Hardware problems are notoriously difficult to diagnose remotely. The PSU suggestion was a fair one, unfortunate that it doesn't appear to have done the job. The next thing to suggest is strip the machine down to basics, ie remove all but one RAM stick and try to get it to boot, then if successful slowly add the peripherals until the problem is identified and replace the duff component. From the sound of things this is what your Techie mate will be trying. Lets hope he/she succeeds.