I need a maintenance manual. Any suggestions? My RT-112 slowed down & stopped, I am trying to open the lower motor section to blow out all the dust! AZ is hot & dry!!! So, I need to dissemble the unit. A maintenance guide/manual would be greatly appreciated! Even a hand-written guide would be greatly appreciated. I have the Instruction Manual, from this site. Thank you in advance! pcwiz p.s. It is black & yellow, & has a full spool of cord.