Originally posted by Treker A quick & easy thing to try is to take a clean soft pencil eraser to clean the camera battery contacts and also wipe down the batteries to remove
any oil from your fingers. That has worked for me a couple of times.
For the mirror, take the lens off and gently press on the foam mirror bumper, if it feels sticky or does not spring back readily it will need to be replaced.
If you continue to use the camera with a sticky mirror bumper, tiny bits of foam get thrown on the mirror & focus screen and can be impossible to clean off.
I also agree withe Steve, and recommend sending it in for a CLA. Eric has my ME super right now.
Thank you for the tip, Treker. Unfortunately, it did not work. It's pretty sure that electric circuit is broken someway. I'll try to disassemble the camera deeper and just after it's almost 100% to send it to a tech, as I have no idea in its mechanics and electronics!