Advice needed regarding Powersoft Digam 7000

Hope you can help me, I have 4 powersoft Digams (2x7000, 1x5000 and 1x3000) and they have been absolutely rock solid since i got them a good few years ago.

Problem is that 1 of the Digam 7000's has developed a fault when sometimes it does not power up straight away, it either takes a couple of flicks of the power switch or leaving it switched off for a while before switching it back on.  Once it powers up it works perfectly and the output is clean.  I am presuming its power supply related, does anyone here have any schematics for the amp? I have hunted for them on internet and cant find any! 

Also has anyone come across the problem before, if so was it an easy repair?

 

Thanks in Advance

 

 

Pete Macmillan