Hello and thanks as i bow to the guru's of E28's

i have 84 533i. and the dash computer was working then i had a fog light switch melt down. and all the grounds going to the ground block under the driver side dash went up in smoke. Well i replaced and rewired all the grounds. but the dash puter is not working anymore no lights at all i have the 12 button kind.

So how do i truble shoot the puter to make sure i did not fry it
or could something is unplugged ?