This was a pretty straight forward repair. This Echoplex ep3 came in and was not working in "echo" mode. It had a bad play head. The customer did not want to spend the money on the head so we used the "sound on sound"
 head to replace it. He has a spare tape which was bad so we kept the original tape, cleaned and demagnetized the heads and capstan pin, cleaned the pinch roller with "rubber renew" cleaned the belt and belt path, and calibrated the whole unit.