I received my new black cable and replaced it this evening, painstakingly going through all the steps to get it perfectly in place. When everything was in place, I plugged the machine in and turned it on and saw a faint pink-red glow from behind the laser tube. Then a tiny puff of smoke appeared under the glass so I quickly unplugged it. It smelled horrible and I grabbed the flashlight again, looking for the source and found the circuit board where I had inserted the black cable appeared burned. Pictures here:
Presuming this is not something I will be able to resolve at home or with a replacement part. Posting here to get some help from support. Thanks!