I bought (won!) a very nice example with a battery leakage problem - meter Non-op - mechanically OK. I did the basic cleaning/polishing, continuity check - problem remained, battery check also non-op. Several days later I resumed my efforts - camera had grown a new problem. The mirror is now locked in the up position, film advance moves too freely (shutter not cocked) and the shutter release button is encountering no opposing tension. Any advise appreciated - especially if it avoids removal of the top cover (never done that). Note: Stewartprat reported a very similar problem with a Pentax ME Super - my Yashica also has (an early) electronically timed shutter. Will I need to solve the battery problem before freeing the mirror? hope you are there Ethostech.
Thanks...Joe