Lately my 1000s has been acting weird. When I cock the shutter, the mirror locks up. So now, I have to compose, cock and then fire. It's manageable but a pain. The battery is fine. I'm guessing the problem is in the mirror mechanism, but not sure. It's likely due for a CLA, but maybe someone else has successfully solvesd this problem?
A CLA is the solution, mine did this a couple of years ago and the only thing that fixed it was a trip to the doctors....something in the electronics screws up and they need to replace a small IC in the camera. I think it cost me about $150 US to get fix, which at that time was not bad, now a days, you might be able to purchase another good working body for that price.