Yeah....look under the reel assembly.
There's a white Molex connector with 9 male pins.
Visually inspect the male pins coming out of their holes.
Are all 9 pins equally sticking out in length or is perhaps one of them slightly lower than the others?
It could be just getting a bad connection when the motor vibrates as it starts to spin.
You might just have to push the shorter pin further into the Molex connector housing hole from behind to get the tangs on the pin to lock into the Molex connector housing hole better so it doesn't back out.
Since you've already swapped the suspect reel into a different location, I don't believe there's any problem with the reel harness.
Another problem could lie with a broken optic tang on the reel basket half that has the optic notches.
Another reason the optic tangs can hit the optics is the split ring...is it still on the end of the reel basket?
Those can be picked up at a good hardware or auto store
However, if the basket optic tangs are busted, you will need a spare reel because something got loose and the notch may have hit the reel optics where it goes in between, breaking off a notch.
Let's see if we can fix the suspect reel assembly before buying one?
If you do decide to get a spare reel, just about any of our NLG vendors on the front page of the website and even our loyal members may respond to help you out and get you a reel for your machine...all you would need to do is place a WTB ad in the Classifieds section of NLG.
BTW everybody calls me Bunker....less typing