Toshiba MV13P2

since it fast forwards, and rewinds, my first guess (that the take-up mechanism is worn, which also causes the machine to "eat tapes" after it stops) not likely..... the other common problem is misaligned sensors (especially if you recently had a tape jam in it, or found a foreign object, like a pen, or piece of candy in it...... another possibility is that if it's with a particular tape, you may have visible gaps in the coating on the tape, which would trigger the sensors, basically saying "STOP.... END OF TAPE..."
there are other sensors and sensing conditions that could cause the same problem....... have the mechanism and electronics looked at by an expert.......

If a tape only plays for a few seconds and stops, its mostly a problem with the counter or the counter belt if there is one or the sensors under the takeup or suppy reels. Did anybody say the unit was eating tapes?? Did i miss something?? Most likly its not worth fixing unless you can take off the reels and clean off the sensors to see if that helps or see if the counter works in FF and rewind and if it does is it a steady count the counters doing. Or is the counter stopping and going intermittanly? If thats the case, then the sensors are dirty or defective. If they are defective the unit most likly is not worth fixing. Good Luck