I often find the repair solution is heavily dependent on the budget.
If you have a large budget, take a bat to the thing and order a new one.
Medium budget, replace random parts until it works again.
Tiny budget, do an in-depth analysis, find out the actual problem. In most cases the problem is software related or user error, then remove the problem software and update your drivers to fix it then don't repeat whatever you did to cause the problem in the first place. If not, replace the only part that has failed.