Celestron CGEM mount

[Mr Jack Martin]

I am getting a ‘no response 17’ message on the handset.
It could be the main circuit board?
Does anyone know where I can get it tested repaired replaced.
Thanks,
Jack

[Nick James]

I have a CGE which, I think, is similar to the CGEM and get these messages every now and again. It is usually the RA/Dec cables between the mount controller and the motors which are pretty rubbish. If you disconnect/reconnect the connectors it often works or give them a spray with some switch cleaner like Servisol. I think it is unlikely to be the main board. Much more likely to be a bad connection somewhere.

[Mr Jack Martin]

Thanks Nick I will check the cables.
I enabled the notify tab but it doesn’t work?
Regards,
Jack

[Trevor Emmett]

Hi Jack,

I believe the CGEM mount (like the CPC alt-az) is essentially ‘dumb’ insofar as the computational heavy lifting is all done by the hand set. The mount ‘only’ contains motors and a few circuit boards for controlling them. The error messages you have refer to the failure of the hand set to communicate with the mount.

I had a similar problem with my CPC1100 some years ago:

‘….On power up and after the ‘verifying packages’ message I get a ‘no response 17 invalid model’ message. Pressing ‘back’ produces a ‘no response 16 invalid model’ message. Following advice from Celestron’s website, I’ve tried cycling the power, repeatedly pressing ‘back’, and trying the hand controller in the the two AUX sockets. None of these things have worked. Various people on the web suggest other fixes but these are generally out of my comfort zone (dismantling the ‘scope etc.)….’

I was eventually given the advice (from someone at David Hinds, just before the company’s demise) to leave it for a while then try again. It worked!!!!! The problems occurred during the lock down (5 years ago-ish) and have not returned. One thing I didn’t (couldn’t) try was trying a different handset to see if that worked.

With David Hinds now gone I’m not sure who handles Celestron servicing now. Tring Astro?

Good luck anyway.

Best Wishes,

Trevor

[Mr Jack Martin]

Nick,
I checked the cable connections still getting the same error message.
Regards,
Jack

[Mr Jack Martin]

Trevor,
Thanks for your advices.
I have a StarSense handset which I will try.
There was an issue with after a firmware upgrade, work in progress on that fix.
Regards,
Jack

[Mr Jack Martin]

The StarSense handset fired up.
I need to test my NexStar handset on another mount to confirm its faulty.
Any offers?
Regards,
Jack

[Robert_Sayer]

Hello Jack,
How did you check the connections?
I have an old Nexstar GPS 11″ and the No Responce 16 and No responce 17 were a common occurance.
As Nick mentions the connectors are rubbish and really not fit for purpose.
I found that you have to remove and replace each connector 2 or 3 times. This wipes the surface of the connector and as mentioned there is no harm using a good contact cleaner to help.
Afterwards I used a contact grease (sparingly) before final re-connection. I have not seen a no responce message since, (touch wood).
I do not know if the CGEM uses the same or similar connectors but on the Nexstar 11″ GPS it is possible to put them back wrong so befoe doing anything take a photo so you know exactly how they are connected.
Cheers
Rob

[Mr Jack Martin]

Robert,
I checked the connections by removing inspecting replacing one at a time all looked ok.
The fault could be the NexStar handset.
Until I test on another mount or try another handset I’m guessing.
Thanks for your input,
Jack

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