488 MKII counter issue

[Capeck0112]

Hello,

I am working on a 488 MKII and I have an issue where when you engage the play/rew/ffw the tape head will engage for just a second then disengage before the counter can even change to 1 second.

I have replaced the belt, motor, gear c as well as looked for any components that look bad/damaged.

I read on a couple other forums that it could be the hall sensor that controls the digital counter but I am having trouble finding what that part is, or where it is on the machine to replace.

If anyone has had this issue or knows where the part is located it would be greatly appreciated! Thank you!

 

[Jack Saturn]

If it is in fact the sensor, it's likely the black and white checkerboard pattern on the underside of the take-up reel. The sensor is watching the alternating colors to ensure that the tape is moving and also to increment the counter.

Alternately, you might check to make sure there is no corrosion on either of the leaf switches that get pressed when a tape is inserted. Sometimes there will be corrosion on the surfaces that touch in these switches, preventing them from making good contact, so the mechanism may think that the tape has been removed.