12"Lx200 focus problem

I recently purchased a second hand LX200 12". There appears to be a fault with the focussing. I have been attempting to star test my new scope. However The scope will not stay focussed, it slips out of focus all the time when looking up. I am aware that it is the main mirror which moves during focussing in these scopes. When I focus a star the mirror appears to slump out of position all the time. The focused image just starts to bloat and slips more and more out of focus This of course renders the scope unusable and I am very concerned about it.
Have you seen this discussed anywhere in the www?
Any discussion of this problem would be appreciated.
Thanks
Gerry

Gerry, try the MAPUG website---it is an invaluable resource for all things LX 200.

Jeff

I recently purchased a second hand LX200 12". There appears to be a fault with the focussing. I have been attempting to star test my new scope. However The scope will not stay focussed, it slips out of focus all the time when looking up. I am aware that it is the main mirror which moves during focussing in these scopes. When I focus a star the mirror appears to slump out of position all the time. The focused image just starts to bloat and slips more and more out of focus This of course renders the scope unusable and I am very concerned about it.
Have you seen this discussed anywhere in the www?
Any discussion of this problem would be appreciated.
Thanks
Gerry
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I had three 12" LX-200's, they all had the same problem!
I used the JMI-NGF-S that solved the problem.

Chas P.

My 10" Classic, (1998)came from the factory with this problem. What I found was that the focuser knob wasn't threaded all the way on the sleeve that attaches to the mirror. Try pulling in/out on the focuser knob and see if there is any slop between the focuser knob and the back of the scope/nylon bushing. I had to run a tap down the inside of the knob and clean up the threads on the sleeve before it would thread on far enough. The focuser is a mechanical linkage. If there is slop e-mail me and I'll tell you how I fixed it.