[UK-CONTEST] PC failure

[frank]

During a very brief hail storm last week there was a single lightning flash which knocked out the power to homes in our local area.  When local power was eventually restored 8 hours later, I found that I could not power up my PC, a machine which is used extensively in contests  The only evidence of life was an illuminated green LED near the RAM sockets on the motherboard.
I have replaced the PSU with a new one but to no avail.  I get the impression that some feedback from the motherboard is needed to prompt the PSU to start up.  Can anyone advise me whether or not there is there likely to be anything simple that I might be able to do to get the PC to power up, or is it a replacement motherboard(or PC) job?
You can imagine my frustration because I have only just got my antenna system up and running again after violent winds damaged them all at the end of January.
Please reply directly to myself.  Many thanks.

Frank GM3JKS