Wierd shuttle sn45 problem?

[Cyrus]

i built a pc around an sn45 shuttle 2 years ago for my bros girlfriend. In the past few weeks a funny thing has happened. If you push the power switch it wont turn on straight away, but if you leave it for 5 minutes it turns on and then boots up?

Wtf could that be, psu on the way out?

 

[Cyrus]

what would be symptoms of a dicky cmos battery lads?

 

[Cyrus]

ill try cmos first, no spare psu, plus its cheaper

wheres the cmos on the sn45 anyone know, she lives miles away rather she did it herself!