It's possible you are experiencing the issue that Gene discovered. See his web site for more info:
http://www.geocities.com/lynol1000/as494/
When the 494 is provided a low input voltage, it will lock out. Changing batteries doesn't seem to fix the problem.
If you're not technical, I believe he saying that simply 'upgrading' your Autostar will bring it back to life.
This only effects the older firmware versions. Unfortunately, Gene doesn't say WHAT the older version are. (?) Nor does he indicate which 'newer verions' will Fix it.
(funny, Weasner's site doesn't list the 494 version either, nor does Meade. :-(

Email him (Gene) for more clarification.

Bill