Test the brushes by catching it in a stalled condition when you have it triggered, then rotate it slightly. If it takes off suspect the brushes or a dead segment on the comutator.
If it doesn't respond to this, then consider the VSR trigger... open it and test by bypassing it when in stalled condition...
Possible reasons for this behavior:
Blinks Long (Red Light): If your battery is too hot, the charger will blink the red light rapidly and for an extended duration. To prevent this, ensure that your battery is not exposed to direct sunlight or excessive heat. Give it some rest to cool down.
Blinks Short: If the battery is too cold, it will blink short and fast. This could be due to prolonged exposure to cold temperatures or the battery being idle for an extended period. Allow the battery to charge for a while or bring it to room temperature to resolve this issue.
Blinks Very Fast (Doesn't Go Away): If the light is blinking very fast and persists, it indicates that your battery has gone bad and needs replacement.
A photo would greatly help with your issue, are both wires still attached to the capacitor?? in not, the capacitor must be replaced with one of the same value,
if the capacitor is ok, look for a wire with solder on the end but nothing else attached to it, or a solder point on a card with a hole in it or a solder joint that has broken free from the card,,, if you can solder well, and have the equipment,. it is good at this point because You'll need to re-solder them back together,,
again a photo will help me greatly in telling you exactly how to fix
https://www.youtube.com/watch?v=pNDgV_6k12E
Reverse and Forward Mode: Try putting the drill in reverse mode and hit the trigger, then forward mode. If that doesn't work, tap the tip on the driveway but don't slam it. It should release .
Use a Wrench: First, make sure that the chuck is in the locked position. Next, use an allen wrench to loosen the set screw on the side of the chuck. Finally, unscrew the drill bit from the chuck .
Remove Chuck Collar: Use a wrench or pliers to loosen the chuck collar and remove it from the chuck. Then, use a screwdriver or other tool to remove the chuck jaws and any other components that may be blocking access to the stuck drill bit. Once these components are removed, you should be able to access the drill bit and remove it from the chuck .
It's going to be a zener diode, that's the easy part, you will need to know the voltage as well, only way to know that is find a good charger and measure the voltage drop across the diode with a multimeter or find a schematic.