Lytnup

Having issues with my Indus GT giving me a "Boot Error" when I try and load DOS and a G5 error for all else. The drive when empty goes from 00 to 39 and stops there. It sounds fine, no unusual noises. Want to clean the heads, but not sure where they are. Can someone send a pic or directions? Trying to get this system working again. Pristine 800 XL with Indus Drive in case with all documentation and discs...even have a Gemini 10X dot matrix printer. Thanks, Lytnup