look for excessive lambs wool in the area around the armature/commutator. Then look for the commutator being cupped real bad and if so you would need to replace it or have it turned at a repair shop if it is not that bad. Clean the brush tubes also to make sure the brushes move freely.
Well, it sounds like you have a belt sander. I would start by sacrificing the towel and the belt. Even if you tried all day and were able to save them they would probably look like they got caught in a sander. Get a utility knife and change the blade, you will want a brand new sharp blade for this. Start by cutting as much of the exposed towel off as you can. Remember, at this point the only thing you might be able to save is the sander. Cutting off the belt will relieve the tension. When you cut the belt give yourself enough belt on ether side to get a good grip. You might need to pull the belt back and forth as you remove small pieces of the towel. A good pair of pliers might help grip the towel fragments. When you finally do remove all the towel and the belt, take some time to look around the drum for fibers that might be stuck in the bearings and pull them out. You may need needle knows pliers for this. Keep the towel shreds for sating rags to finish the project you're working on so it will not be a total waist.
Good Luck
Ray
Google doesn't seem to be able to find the part number you supplied...
Check your instruction book but I believe the flashing red light to mean the intelligent charger is refusing to charge the battery because it has tested it and found it faulty but there is no way of knowing what the fault is.
There is a temperature sensor inside the battery and perhaps that has failed the test - or it could be a crystalised cell that has been discharged too long - or it could be the battery is trying to consume too much current - or perhaps it is open circuit and consumes nothing...
You may need to change the brushes if it is a brushed motor. When you do this you may need to clean the armature with some contact cleaner and a rough cloth to remove and build up of gunk.
It's best to change brushes early, as overheating due to wear can cause damage to the armature and brush holders. New brushes are easily found online, and very cheap.
See here for a demonstration of how to change brushes.
https://www.youtube.com/watch?v=ffXyDqPXCNE
If you are certain your batteries charge on another charger then its time to replace your charger - there are no serviceable parts in it.
Or you can sell it as a music box...
Have a close look for plugs covering hidden screws. Most power tools now have security screws in them to stop people opening them up. You may need to buy a set of special screwdriver bits to get these out.
