OK the belt tensioning mechanism is spring loaded. First what is the quality of the belts are they real flimsy or stiff. You say the rollers spin but my question does the rear roller still spin and the belt remain stationary. If so the rubber belt on motor is bad. I would take a look for excessive wear on the rear roller. Does the yoke mechanism snap forward or move slowly, look for a build up of sawdust in this area that might be restricting movement on the yoke. The wear plate in still good condition. One other thing on the belts are they directional? Do they have an arrow on the inside if so that has to point toward front of tool. I looked at a breakdown and could not see anything else to suggest. I never had this problem except with belts when I was at Makita.
Likely the gear belt that drives the drive rollaer has failed. Either it is totally gone or the teeth in a spot have been destroyed and the motor is just spinning the sprocket in the belt. The belt is about 1/2 inch wide and is covered by a belt guard.
if you have compressed air remove the dust bag and blow thru every port and opening you can find. Make sure to wear safety glasses. Then I would run the tool with the dust port facing away from you, there is a buildup inside not allowing proper flow, you should empty the dust bag when half full for maximum performance.
You are probably missing an insulating ring / washer that goes between your bearing and your armature (the shaft on the center part of the electrical motor. The fact that it does not have a grounded plug is not necessarily an indicator of age or safety so don't be too afraid. DeWalt still uses two prong cords to this day. In these tools they offer what is called double insulation, simply non-conductive material that separates electrical components from the user. The part number for the insulating ring is 681623-9. If you ever wanted to ground the tool you don't really need any special switches you just have to attach the grounding line to the metal casing.
The brushes are easy to check and replace. You will see a small disc to the right of the handle on teh motor body, and another on the front side. These are your brush caps. Simply unscrew them and you will see the brushes. They could just be stuck with sawdust so pull them out gently and check the length. Most makita brushes have a wear line that indicates when you need to change them, but generally if the holders are clear and teh brushes are tou ching the motor, the brass head should stick out a few mm before the caps go back on and this should be enough to give you time to get a new set in ready. The brushes will only fit in the holders one way.
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.
