Repaired a Panasonic RX-C45 and played a tape in it. (with the front off) The first side went well, and then I turned it over and played the other side. About three quarters of the way through, it started wowing very, very badly. I'm presuming that the original play of the tape produced tension on the other reel that caused the wow... I'm not immediately suspecting the pinch roller or capstan. I might have just been a moron for playing the cassette without the front on and once I put it all together properly, that all will be fine... however I don't want to do that and then find out I've got a problem and have to take it all off again. Any thoughts please?
I'd say this is worth sorting while open, closing it up should have no effect on sound. Have a look at the tape path and see if it appears smooth, may be that the pinch roller is a bit smooth and may need a clean and a rough up with some wet and dry but first try a different tape, preferably a new ish one that you are confident plays well. I have a few i save for testing as i know they play and the spools are nice and smooth. If its on its original belts the playback may have pushed it enough that the belts need changing.
Had same problem, try to put more tention on pich roller, mybe spring lost tention, or what was for me, tape it self, ff anf rew worked fine but didint hellped,but reading forums sugested too tigth winded tape, i taped hard it, and lefted it playing with wow, aftet few run it worked fine, but part of tape was damaged suspecting by slipping capstan
I had something with a walkman, it played fine in the forward direction but had loads of wow and flutter on reverse play. On closer inspection I noticed that one of the pinch rollers had a a vertical line - probably caused by leaving it pressed against the capstan in the play position. A new pinch roller solved the problem.
