Another typical Zorki 5 and 6 issue is the electronic flash socket not working or intermittent. I know that flash photography is considered taboo with RF cameras in some quarters but since the option is there and for lack of slow speeds it is a nice option to have besides all the Leica Ms have it..
It is an easy fix, on the Zorki 6, remove the 4 screws holding the chrome baseplate. Be careful not to loose the two spacers underneath the two screws adjacent to the latch side. On a Zorki 5, remove the baseplate and then the shroud. The picture above is what you will see after this step. Inspect the circular disc [marked with a red arrow] and make sure the tiny dot is at 3 O'clock [oriented towards the take up spool]. If not loosen the screw at the center and adjust.