It's a very common problem, had it several times on some MX5000/3000. Bad electrolyth capacitors, they need replacement after this long time.
Very common are also bad solders on the mainboard.
Usually it takes 2-3 hours to rework the boards.
As long as there were not burning sounds or smoke, it's pretty easy to repair. It's a Thomson ICC5 mainboard, should be well known all over the world, probably built several million times...
A little guide for this mainboard is in the workbench section in the MX5500/3500 workshop.
Martin