I've had a Pentax MX for a while, never really used it since there is nowhere to develop film around where I live besides walgreens
Decided I might try to sell it so I started testing it out. Turns out the mirror gets stuck very frequently if the shutter speed is set any faster than 1/60". It's like it does 90% of the shutter operation and then sticks.
If I switch back and fire at 1/60 or slower it works fine, getting stuck very rarely. So it doesn't get permanently stuck.
When I do this with the back flap open, I can see that the shutter opens and closes but the mirror stays opened. Also it feels like the shutter doesn't close
all the way (can see the end of the curtain, but there is no light gap).
Anyone have an idea as to what might be going on? I wouldn't want to sell it in this condition and might end up keeping it for any future film endeavors so I would like to get it fixed if possible.