[Startrek (Martin)]

I’ve had my SW 12” Goto freedom find Dob for 6 years now at my retirement getaway dark site and it has performed flawlessly until a few months ago.
Issue is the Azimuth drive will not accept a rate change to a slower slew speed and remains on rate 9 ( fastest ) irrespective of changing the rate on the HC, thus useless for Alignment.
Altitude drive works perfectly at all rates
Scope is stored in garage with cover and is in extremely good condition, no dust , mould , rust on metallic parts etc….It looks brand new.

Action I’ve taken to date ….,
Surfed Cloudy Nights for ideas , answers etc…
Surfed Stargazers Lounge and found a guy who had a similar issue with Az drive on his 12” Goto. He found a suspect loose conductor on the small ribbon cable going to an encoder. He pushed it home and problem resolved.
Called Graeme at SW Australia who suggested a few things to check , which I did below ……,
Updated firmware on existing HC
Replaced HC cable
Replaced motor cable from Alt box Az port to Az drive.
Opened up Az drive and checked motor connector and encoder connections.
Motor board and encoders look in mint condition. All solid clean connections
Replace existing HC with new HC
Disabled encoders on HC
Replace power supply with new

Tested scope both during a 2 star alignment and via easy tracking mode ( scope does track at Sidereal in easy tracking mode ) Same issue Az rate stuck on rate 9 or fast.
Altitude control is perfect on both modes at any rate.

One observation is that when I change rate to say 5 ( mid slew speed ) and attempt to slew scope , as I press the Az movement button I hear a click and no movement in Az , I immediately press button again and scope flies off at rate 9. This occurs in both Az directions. I did try all rate changes from 1 to 8 and same issue , Az flies off at fast rate 9 even though HC says rate selected ( eg 5 )

Az motor slews smoothly at rate 9 and sounds fine , it’s not hunting or making abnormal sounds.

SW Australia do not sell Az motor boards as spare parts ( damn )

I’m almost sure I’ve got a dud Az motor board ????

I’m pretty much got a dead scope at the moment in regards to Goto. I don’t want to throw any more money at it to resolve unless I can find a new Az motor board.

Any thoughts , ideas , suggestions most welcome

Thanks

Martin

PS : I don’t live permanently at my retirement getaway which makes testing and diagnostics problematic. The last time I used the scope and found this issue was Sept / Oct 2024 school holidays