Meade LX200 10" SC Telescope
You have a standard lx200 problem. If you transported your scope a lot with the drives "locked" it damages the RA and DEC drives. If you keep using it, the motors burn out and start drawing too much current. This sometimes blows the motor driver chips on the motherboard which are getting very rare.
The burned out tantalum caps can be replaced with better aluminum electrolytics very cheaply. If the ones in your Autostar burned out, they often burn up the ribbon cable. Also, they often take out U11, a 74LS14 chip on the motherboard. Also a cheap repair. You should take the Autostar apart. If they are burned up, it will be obvious. If your ribbon cable survived, you should replace the caps with aluminum electrolytics. I believe they are 6.8 uf.
So, if you can work an ohmmeter, measure the resistance of the two drive motors with the plugs unplugged. If it is about 14 ohms they are ok. If they are about 3 or 4 ohms, they are toast. Check the worm drives for end play. If there is just a little, you can adjust them. The battery jack on the control panel often breaks the solder joints on the board, causing one of the problems you describe. You can check that and replace/resolder as necessary. The on/off switch often fails and gets intermittent. These are also cheap and can be replaced. I don't repair these for a living but I repair a few of them for friends in the club. These are pretty common problems.
Feb 27, 2008 |