Image of the day

Captured by
Terry Wood

Jupiter (clearer) Nov 5th 2023 w/Mewlon 180c

My Account

New to Astromart?

Register an account...

Need Help?

dead 8" f/10 LX200, suggestions?

Started by tmcdonagh, 06/26/2003 12:19PM
Posted 06/26/2003 12:19PM Opening Post
Transcript to owner:

Hi Carl:

Spent a few hours on your scope last night with no success. I am still seeing controller lockup upon initialization at the "meade" prompt. Checked everything I could check without tearing it all apart. Here's what I did:

Power supply voltage reads 21.1 volts with no load. Should be ~ 18 volts? Could it be the problem? Did you say you tried it with the 12 to 18 volt converter? You may want to asked mapugger's about this.

Checked the DEC and handpaddle cable for continuity. They seemed fine to me. So the cables are fine but that does not mean the sockets are. Can't pursue that any longer.

Pulled the base off. Checked the operation of the RA motor. Seems to turn fine upon startup. Cleaned off the worm shaft of heavy grease buildup where the hall sensor magnet is to no effect. Shorted pin7 of the RA cable to motherboard with no effect.

Checked the battery on the daughter board. Read out 2.92 volts. Shoud be fine but you may want to check with other meadeites.

Performed startup with keypad disconnected. The scope went through the same operation without it

If I had to make a guess, I would say it was one or more of the following things:
Bad cable connectors
Motherboard or keypad daughterboard or entire keypad
DEC motor and or electronincs
RA motor and/or electronics (bad hall sensor, bad indexing ring/LEDS/detectors)

I also noted that the two heatsinked IC's that generally attached to the baseplate via allen bolts did not appear to be so. That might cause failure or erratic electronic behavior due to overheating. I never opened the baseplate before and noted the allen bolts were not flush with the baseplate when I received it from you. It must have been from when you first removed the baseplate as they were always flush to the plate in the past.

I would contact a serious repair service, be that Meade or other group and consider a motherboard/DEC/RA motor replacement option. Another option would be to keep your eyes out for a used fork/electronics setup on astromart. Some people pull the OTA from the setup, then put the rest up for sale. Might be cheaper than returning the scope to Meade. Last option would be to pull the OTA yourself and find a decent GEM mount to put it on. The 8" f/10 LX200 OTA is on the high end for weight with the Vixen GP type mount which is affordable and a great astrophoto performer. Proper balanceing would be key.

Let me know what you think. Sorry I could not be more helpful!!!!!

Best regards,

Tom