The 400d body was giving err99 after each shot. The shutter curtain was opening, but closes immediately. It should be the shutter, so I disassembled it.
And I have found 1 of the 4 screws, which hold the main PCB hanged on a piece of isolation tape… I wonder how many times was it jumping from one side to the other of the body, before getting captured by the tape.
The other 3 screw were totally loose in their place.
Interesting is, that the body was 100% never disassembled, as it was bought in the original box from an official shop. That means, the screws were not tightened in the factory.
If you open the body, You can’t go back for warranty.
If You bring it to the official servicepoint after the normal warranty, You will never know, that it was a flying screw in the inside, which killed your shutter (for example).
Anyway, the 350d and the 400d are not my favorits, from the technical point of view…