Quote Originally Posted by AgX View Post
To my knowledge there was not such as T-90 diagnosis computer (a good idea though). At least there is no diognosis plug at the camera circuit to connect to a diagnosis computer.

I just bought a pristine but dead T-90. I shall still try to cope with the eletrical/electronical fault by means of multimeter and oscilloscope.
As I wrote my information came direct from the mouth of Canon's national service manager.