I have a Sharp video recorder that stops playing tapes, at first this happened after the tape had played for about half an hour but now stops after only a few seconds. I dont have the model number to hand but it used to automatically slow down when rewinding or fast forwarding a tape as it got near the end so as not to harm the tape but this also stopped working. I don't know if the 2 problems are related. Is there something that just needs cleaning ?