Meade LX200 GPS 8" "sensor board" error message

[musca in soup (Jim)]

Hi all, When I start up my Meade LX200 GPS 8" an error message appears on the Autostar II screen that says "The telescope cannot communicate with the auxillary sensor board".

Any suggestions on what I should do?

It is unusable because it cannot get itself any further.

Jim

[AndrewJ]

Gday Jim
The sensor board is powered on/off using a transistor switch on the mainboard, and is only turned on as reqd.
You can use ( <mode> IIRC ) to get past that message and the scope will happily work, but it means the autolevelling etc will be disabled. The scope will still work correctly and happily if manually aligned.
That said,there is a small board in the left fork arm, between the main board and the level sensor card. The error you get occurs if that board doesnt respond when booting up.
The reasons could be many, and need a bit of digging, as it may also be a fault on the main board transistor switch.

Andrew

[musca in soup (Jim)]

Hi Andrew,

Thanks for reply.

So I've just had a panel remove-a-thon and located the sensor board and the other one you mentioned in the left arm. Nothing appears loose up there but I disconnected and reconnected the stiff grey flat wires joining them together.

The wires then dive down the left arm and reappear in the base. There are two connections at the bottom end of these wires that were not attached to anything. One (6 pins) may have come from the board directly under the front panel but the other one (9 pins) doesn't seem to go anywhere. When I connected the 6 pin end it was no different. Same start-up error message

I could not be sure which part is the transister you described.


Addit: FIXED!!!

I typed "Meade LX200GPS circuit" into google images and this image popped up http://www.cloudynights.com/topic/91...ng-hard-stops/

Turns out three loose connections, so obviously pulled out somehow. I suspect it may have occurred when attching the scope to the tripod in the dark one night.

So thanks for your help but seems to be good now.

[AndrewJ]

Gday Jim
Just for others who may find this thread later
There are full circuit diags and a lot more piccies in the files section of the Meade LX200GPS yahoo group.
Well worth bookmarking it.
https://groups.yahoo.com/neo/groups/LX200GPS/info
That said, im a bit confused????
There is a 9 wire header comes down from the left fork arm
and a 6 wire cable coming down from the right fork arm.
The 9 wire is the one from the sensor board and mounts to J5, the header in the middle of the main board ( by the power switch ).
The other 6 wire is the DEC motor card wiring and goes to J9.
I cant see how mounting the scope to the tripod could cause these to pull off, unless you have an older model that has a threaded steel insert in the base of the scope ( that the 1/2" rod threads into ) and that is also very loose. Ref black steel insert in piccy
You need to confirm that this is not loose, or it may happen again.
If loose, just screw it up tight as you can.

Andrew