MPC 2000xl white screen and LED problem

I have checked on the power supply board for blown fuses but did not see any that were black/discolored but i swapped them out anyway to no avail. I will ask the shop again for clarification when i pick up the unit. The shop was a certified akai repair shop and i was referred from the mpc website. They took a very long time with the unit (more than 3 weeks just for the diagnosis) so i am hesitant to have them keep working on my machine.

I do not have a multimeter at the house but i could use the one at the lab at school. What kind of things would i test for?

As soon as I get my mpc back i will try disconnecting and reconnecting everything and let you know what i find.

Test if it boots with the options disconnected, before reconnecting anything.