CGE RJ-45 pillar-to-head cable problem

[sculptor]

Greetings,

Occasionally my CGE starts making sudden small jerky slews all on its lonesome, or more often fails to respond to (say) a request to slew in one of the four directions (eg East). Multiply giggling and unplugging and replugging the relevant (Eg RA to RA) RJ-45 to RJ-45 patch cable from pillar to equatorial head seems to fix the problem for a few days or so.

I've tried blowing out dust and cleaning the contacts with isopropanol.

(The RJ-45 sockets at the eq head end seem to be really badly thought out. They are in almost impossible positions and hard to get at. A short fly-lead with a 9-pin D-connector would have been a far more robust solution.)

After checking that the two patch cables seemed to be "straight through" rather than "cross-over", I replaced them with JayCar Cat-5 cables. Problem much worse, with scope no longer accelerating smoothly but jerking. Put back original cables and put heart back in chest-cage. All currently working, but bound to go wrong again in due course.

Any one else found these cables or their sockets (marked RA, DEC) to be dicky? Any solutions? I don't want to put the scope in a crate to the USA, to be ignored at Celestron's leisure, what with the best viewing months coming up.

[Dennis]

Wow – this is a tough one!

Initially, I considered that jerkiness might be an indication of too tight a mesh between drive/worm gears, but upon reading further, this seemed less likely?

Swapping the cables between OEM and Jaycar brands produced a surprising result? Were the Jaycar cables much longer? I guess that differing electrical properties of the cables could affect the signal strength? A weak or intermittent signal might cause the mount to stutter?

Is there a battery somewhere in the system whose voltage is falling below a certain threshold?

Is there a Yahoo Group for your mount – someone may have experienced a similar problem already, and there may be specialised advice over there?

Hope you manage to fix it.

Cheers

Dennis