Greetings,
I think some history about your device would be helpful. Did you buy it new, are you the original owner, etc.
Do you have another battery and memory card to test it with?
Since your camera has an articulating screen, please change its position to various different angles to see if the screen works in a different position.
Now power the camera off, and remove its lens and memory card. Power the camera on again and perform the same steps. Any changes?
Check and clean the area around the viewfinder. As the other posted stated, there is a small proximity sensor that disables the LCD when you bring the camera towards your face.
If you can see the camera's menus in the viewfinder, perform a settings reset, then power cycle and retest.
If none of these actions help, I'd log into MyCanon and create a repair request.
https://myprofile.americas.canon.com/
You will receive a cost estimate. A used M50 on KEH sells for about $440 in EX+ condition. With this information, you can decide the best path forward.
Repair, replace, etc.
~Rick
Bay Area - CA
~R5 C (1.0.6.1) ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, +RF 1.4x TC, +Canon Control Ring, BG-R10, 430EX III-RT ~DxO PhotoLab Elite ~DaVinci Resolve ~Windows11 Pro ~ImageClass MF644Cdw/MF656Cdw ~Pixel 8
~CarePaks Are Worth It
