Technics RS-TR272 dual cassette deck

Ahh, Another Dual cassette deck. These are typically not worth a repair charge. I went looking for a service manual but Hi Fi Engine did not have one but they had a Owners Manual. Any unit that has a specification as to wow and flutter starting new at .18% was never made to be a long lasting deck of any quality. I don't like to be negative about people equipment but you might be better off getting a better deck from the start. If you think it is worth the repair, then send it to someone but I don't think you will want to sink $100 into a unit like this.
I am not saying it is unrepairable but that with what you come out in the end you could have made a better choice for a deck to buy.
It is probably a bad solder joint or bad capacitor on the circuit board.
I am in Chicago and would look at it for you if you want.

My RS-TR272 tape deck plays the cassette but no sound. I have not even used it much, may be 3-4 times in last five years. I tried demagnetizing it but still no effect. It is brand new unit, only thing I did last time was that plugged in the RCA cables in opposite ways one time (Output in In and In into output one). I am not sure if that had any bad effect on it. Can someone please help on this as unit shows cassette playing. There is no volume switch on the unit itself as someone else recommended in the previous answer.