A similar thread on Blue Room suggests they all use the same voltages (+/-17V plus 48V for
phantom power), so a higher-rated supply would be fine. Unfortunately Soundcraft don't
have info on the DCP-100 - too old for their online spec sheets! Try ringing them,
perhaps?
Repair might be cheap if you're the repairer. If you need to pay
someone to do the repair, costs could rack up quickly though, which might be overkill for
a rather old desk.