Good idea to always replace the power and speed control as a pair.
When the darlington fails it can output full potential and will slam the doors open and close. I would replace the power board and then re-adjust your speeds before going any further.

If its been really hot for a long time it can sometimes cause issues with the socket board below, but only in rare occasions.

Good chance if you still have an original one its probably time to replace anyway.

The 104 is a nice upgrade but requires a piggyback board if you're local code requires a door holding signal while the car is in motion.