Upon trying to use this tape player I found that it was ravenous for tapes. I disassembled it, cleaned the tape head and pinch roller but it still mangled my tape. Observing the mechanism during play, the problem appears to be the tape sliding up along the pinch roller (see photo with directional arrow) until it creases the side and begins munching. I have already cleaned the pinch roller. Would replacing fix the problem or is there some other alignment issue? This problem appears to be less likely if on the player is set down on a surface where gravity is pulling it away from the direction in which the pinch roller wants to slide the tape. It is much more prone to slide along the roller if the player is upright. I think the pinch roller might even have a very slight wobble to it. The pinch roller dimensions is 9x6mm for the rubber and 6.9mm for the sleeve.
How does the roller feel, is it glazed and hard or slightly elastic? You may be able to use Rubber ReNew and get some life back in it. Over time these can get hard when the softening component dries up. I've posted two really good articles on basic tasks in the boombox tech section, if the roller is misaligned or there's not enough pressure, it may eat tapes. http://stereo2go.com/forums/threads/audiocassette-recorder-adjustment.5191/ There's another article down there that talks a little more about repair work as well. https://www.amazon.com/Chemicals-408B-1L-Rubber-Renue-Liquid/dp/B008O9X3KS?th=1
You need to replace the pinch roller. Rubber Renue may improve the old roller temporarily but it will soon fail again. Once the rubber has gone hard it cannot be reversed. If the roller has a noticable wobble on it then Rubber Renue won't do much good. The importent dimensions which you need to note are the outer diameter, width and the diameter of the centre hole (typically 1.5 or 2mm). New rollers are easily available. Stereo2Go member "Mihokm" has a good selection available on his website: www.fixyouraudio.com or on ebay. As Mister X suggests, check the pinch roller pressure too.
I was looking at the recorder, I'd do the least amount of work, it looks like a dictation machine, I wouldn't throw too much money into it.
