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Celestron CGX Nexstar


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Hi,is there anyone out there who can help me with a problem im having with my mount,the mount is the CGX,the problem is that when i turn it on the nexstar hand control displays a message (no response 17 invalid model)

can anyone tell me how to fix this,many thanks.

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  • 1 month later...

Have you had a look on the Celestron website?  This has been copied from it.  Not sure if it helps.



 | Date Posted: 11/19/2010

"No response" means that the hand control has lost communication with the electronics board within the base of the telescope.  The number following this message will indicate the address of the component that has lost communication. 16 indicates the azimuth or RA motor board, 17 the altitude (declination) motor board. Unfortunately, this number doesn't tell why the error has occurred. 

To clear the no response messages, repeatedly press Undo. This fix may be only temporary and does not address the potential underlying problem.

There are several reasons why this error message would appear.  Insufficient power is the most common. Check your power supply.  If the DC battery is low, the scope will be unable to communicate with the base of the telescope.  If you are using an AC adapter, please make sure that the adapter is rated for an output of 12 volts DC at a minimum of 2500 mA (2.5 Amps).  If your adapter puts out less current than 2500 mA, the scope will not be able to communicate properly. Check all power connections including the power port pin for solid connectivity.  

If you have a cable in the PC port (of a mount that has a PC port) that is not connected to anything, then this can also cause the messages to appear.

The next potential causes: the hand control, the motor control circuit board, the motors, or the cables-wiring-connectors in between.  Plug in the hand control to an AUX port and see if this eliminates the message. CGE DEC and RA cables are easy to check and swap around to see if it's these cables or their ports. Advanced GT mounts similarly have the DEC cable that might be the problem. Try reflashing (updating) the motor control firmware. If you are able to update the hand control but not the motor control, the problem is most likely the motor control board.

A computer crash or communications break between your PC and the hand control during an MC update may result in either “Initializing”, blank screen, “No Response 16” or “No Response 17” messages. This will prevent your updating the MC for your mount. To clear the no response messages, repeatedly press UNDO. Then proceed as usual with the MC update.

If these ideas don't work, it’s best to send the mount and hand control back to Celestron for factory service.

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