K-1000 Count`s wrong

Hello everybody,

i have a Problem with my Yamaha K-1000 Tapedeck.

After i align everything (PB Level, Record Level,Azimuth,...) according to the Service Manual, the Tapedeck Counter doesnt work as well as he should count.

When i listen to 45 minutes Audiocassette, it count`s only about 22 minutes.

When i winding forward/rewind its almost the same (indication of 22 minutes Tape length). It should be ~45minutes.

Is there a trimmer (Potentiometer) where i can align the Playtime?
Or how indicate the K- 1000 the Playtime ? So that i can take a further look to the functionality to look for the fault.

The Speed of the Cassette is normal.

thank`s

Have a look at the photo interrupter- it sounds like it may be missing a vane or a marking.