my 5d ii suddenly died!
I used two 5D II professionally for years until last month and never had a hit of trouble-- (49,000 clicks on each camera). Bummer that it cratered like that--unusual. Sorry that I don't have a clue why it failed.
But I would check how much the shop is charging for the repair. Might be more cost-effective to buy a refurbished 5D II or new 6D.