I decided to take a look at why my 4041 thermal printer was printing unrecognizable characters.
I was able to fix it by removing the timing disk cover and cleaning the contacts and timing disk with 90% isopropyl alcohol.
I believe the 40 year old grease on the timing disk had hardened and was keeping the contacts from making proper contact with the timing disk.
You can see description and photos of the repair on my post on vcfed:
