Uploaded July 2021 | Updated September 2026, 2 weeks ago

---

This Teac R-555 stereo cassette tape deck from 1984 actually contains some dormant logic circuits for a more expensive model. In this video, we activate those extra features. A few months ago, we repaired this deck by replacing a belt, some bad resistors, and shorted capacitors. Shortly after that repair the cassette player died. Using a second deck we were able to get it going again. During the process, we noticed several circuit boards (and the manual) had notations for the next most expensive model, the Teac R-666X. As it turns out, we could just add 3 switches and and L.E.D. and get those music search features - a simple but effective hardware hack!

0:00 Intro
0:33 Previous Failed Repair
0:50 Comparing to a Second Deck
1:48 More hidden features inside?
2:05 Switch and LED Placeholder test
2:25 New Time-Based Counter
2:45 Computronic Program Search
3:10 New Memory Start Button
4:10 New Block Repeat Feature Demo
4:37 Conclusion

Here's the original repair video and review/look at features:
youtube.com/watch?v=1ic_EWfVcSg