I need a parts list for an old realistic ctr-56 cassette tape recorder the drive belt needs replaced it melted

You can try this site that I am listing but if it is not in stock, then you can use the dimensions listed to see if you can find one. SMC ELECTRONICS

Check all capacitors. They are the most common point of failure, next to the rubber belts.

1-800-THE SHACK

Radio Shack Cassette Recorder

Radio Shack Products

Contact cleaner does not belong anywhere near a belt but that is probably not what caused it. You do not list the model number but many tape decks can be found on the PRB cross reference Pdf that is free on the internet. Then you order that belt from Consolidated Electronics. If you can not find the model then measure the path- after cleaning the old belt off with Ammonia or alcohol, then measure with a string and subtract 5% and order the appropriate sized belt from Consolidated.

The cassette belts are not the problem. They are generally universal. All you need to do is work out roughly the diameter of the belt and search for that online.

The roller is the main problem. They are not universal. Each deck seems to have it's own design for them. Some of them will be fitted into a metal/plastic piece, others will come on their own. I would do a Google image search just on "cassette pinch roller" to see if anything comes up like your model.

Or you can look for the service manual for the part number.

Contact RCA for a list of service or part suppliers.

Or find a model like yours on E-Bay or second hand that is going for parts!

If you can get the part from an electronics supply (we have a place here in my medium sized Canadian city). Once you obtain the part it just takes patience and a natural ability at puzzles to be able to replace it. Perhaps you should remove the old one first to be able to size it.

Generally all you need do is measure the diameter of the old belt(s) in mm and type "cassette drive belt ??MM" into google. You don't have to be spot on with the measurements either.

It could be either a worn roller, but more likely a belt problem. It's often a good idea to replace the belt(s) as the are rubber and wear out easily. They are not expensive either. Drive belts on tape decks are mostly universal. You only need to measure the diameter of each belt in mm and then enter the result in Google as "Cassette drive belt ??mm".
Make a note of how it fits before replacing them, that's if you can do it yourself of course!

Sounds to me like the belt drive is slipping!
Need to open her up and check tightness of belt and probably try to buy another one which will be tighter!

How much warranty you have left on that product. It sounds as if you need to get that replaced. Or You need a new button. something may be broken off inside the machine.