I just inherited an orange tube C5 in good condition that has been sitting for years in its original case. Some of the accessories include the star diagonal, a Barlow lens and two oculars, a 25 and a 12 mm. It also has the original tripod and equatorial wedge.
I get decent imagery with just the diagonal and the 25mm ocular. However, if I try to increase magnification with the Barlow or with the 12mm I can't get the image in focus. I cleaned the diagonal, Barlow and oculars with canned air and a camera cloth with no improvement. There was no cover on the visual back and it looks like dust has settled inside the telescope on the secondary and possibly the primary.
The RA and dec adjustments and clamps appear to work well. The focus knob feels a little 'rough' like detents but seems to work just fine otherwise.
What can I do to improve the image quality with increased magnification? I've been poking around this site and haven't yet found a detailed tutorial on disassembly and cleaning. I know next to nothing about telescopes, just enough to be dangerous!
I'll be posting this 'scope in the C5 registry soon.
Thanks for any insights you can provide!