A Celestron CGE Mount – An Amateur Astronomers Journey! Part I

I acquired a rather impressive Celestron CGE EQ Mount at a rather very good price a few months ago which was a big step up from my rather humble Celestron CG5-GT Mount. When one see’s this mount in real life it’s very impressive, it’s beefy, heavy and overall has the appearance of being very solid indeed. It was designed to take heavy scopes up to Celestron’s 14-inch SCT models. The weight of the tripod, EQ head, central column and counter weight comes in around 50Kg, not including the scope, just on the edge of what I can manage regarding portability.Celestron CGE Mounts did have one main flaw and that is the cable design on the RA and DEC axis. It came to light that owners were reporting reliability issues with RA and DEC axis, runaway slew problems, intermittent communication problems, no response errors and other related issues which was down to unsuitable RJ45 cable and socket design. Many owners upgraded to a more robust quality solution using military grade style components such as that offered by Gary Bennett, I’m glad to say my CGE mount has this upgrade.As with any new astronomical toy, it was exciting to setup my recently acquired mount in my office and see how it all works and behaves. Initially everything appeared to be working ok. I use my SBIG STL CCD camera for direct guiding using CCDSoft V5.When testing I noticed one of the guide directions did not seem to be responding. I checked everything I could and dug deep into software, checking cables and connections etc but everything looked ok.I decided to upgrade the firmware for both handset (NexStar+ type) and MC (Motor Control) board which had older 5.07 firmware version, latest version for the CGE mount is 5.20. That went OK but original issue remained.I decided to have a look at the central column where all the electronics are located, again, nothing obvious until I zoomed into the MC board. There I found an IC on the board that had a mark on it, closer inspection determined that this chip at some stage was overloaded for whatever reasons and burnt through affecting only partially the guiding function!The IC itself is a 28 pin 16F based PIC Microcontroller, specifically PIC16F876-20I/SO. Motor Control board is Celestron PN: #NXW411In the meantime while trying to figure out how I was going to repair the issue, I was keenly waiting on other new toys to arrive such as the Pegasus Pocket Powerbox Advanced, ArteSky 70mm f5.7 Guidescope, QHY Polemaster Camera, SBIG Remote Guide Head camera, Gerd Neumann Flat Panel and upgraded cables and power supplies!  In part II I will share how I went about planning and carrying out the repair (and the headaches) to bring this great mount back to its former glory.

Interesting post Mike. Wishing you the very best with your new beast of a mount. And I'm looking forward to hearing how you get on with it.

Clear skies to you,

Darren.