RonTheCat brought his KC tape deck over today for a bit of cleaning with isopropyl alcohol (don't get it on the belts) and testing. We thought the brotherhood might like a bit of a before:
and after video:
Overall electromechanically it seems to be behaving well. The transport has two belts. One is ~19cm x 3mm and connects the main motor to the flywheel, the other is ~8.4cm x 3mm and connects the FF/RW motor to the tape pickup spindles. The pinout of the main power connector when looking at it, pin 1 on the left:
- 1 - Main motor +ve
- 2 - Main motor -ve
- 3 - FF/RW brake? solenoid +ve
- 4 - FF/RW brake? solenoid -ve
- 5 - Playback solenoid +ve
- 6 - Playback solenoid -ve
- 7 - Tape pickup motor +ve
- 8 - Tape pickup motor -ve
- 9 - Not traced
The exact distinction between the purpose of the two solendoids are not really clear at the moment. The one connected to pins 5 & 6 will bring the pinch roller into contact with the capstan. The one connected to pins 3 & 4 will bring the pinch roller forward, but it does not come into contact with the capstan. Both appear to release what is probably a brake on the take up spindles. So it is possible that one solenoid is used for playback, and the other is used for fast forward/rewind. It might also be possible that both solenoids are used in parallel to reduce the load and heating on them. This should become clear when we test the signals being sent to the tape deck by the I/O board.
The gunk around the pick up spindle that was turning slowly seems to have been associated with the "brake", we wonder whether it used to have a rubber pad of some description that degraded over time.
The fact that all three solendoids work when driven directly, but fail to operate when driven by the KC is a little perplexing, but suggests something might be amiss with I/O board.
Overall we have found the tape deck to be less scary to work on than we had thought. If you are competent with a voltmeter, power supply and screwdriver; and are diligent in taking things apart and putting them back togerther, you should be fine.
Obviously if anyone has any more information on the deck, how it works and tips they would be greatfully received.
Edited by decle, Sat Apr 28, 2018 1:03 PM.