First off, I want to thank all members who I have PM'ed for files and software and have delivered! Many, many thanks also go out to those forum members who actively post and share their knowledge base with us. Now for my situation.......
I took a chance and purchased a dead Vetta one combo. Plug it in and nothing - no LCD screen activity, not even at any viewing angle - quiet as a mouse. Took the chassis out and the fuse is good and that is a good thing indication that the boards inside did not get fried. Took Ohm readings on the speakers disconnected from their leads and they read 6.4 ohms unloaded. Now, do I really need an isolation transformer to probe for voltages with my DigitalMultiMeter? I've been reading the service manual and you can't miss this warning. I also tested the CR battery and it is .004 volts. I may take the board out and retest the CR battery not sure I had a good ground. As the amp is 16 years old, I'm not hopeful the battery will give an acceptable voltage reading on my DMM.
Before I Chang the battery, is it worth my time to try a firmware update? I have read that others have had dead screens and updated by Midi and were successful even though they were "Flying Blind".
Here's the link for flying blind at reddit:
https://www.reddit.com/r/vetta/comments/4w5ze5/firmware_update_guide/
Update
I am replacing the original CR2032. Chassis removed from Vetta combo by removing 4 speaker leads and 6 Phillips head bolts. The exterior chassis insulating tape is sticky. You may have to persuade the chassis from the cabinet by wiggling gently back and forth. .
Chassis top is the user interface ( UI ). Separate UI by removing 5 hex socket bolts. Lift UI at that edge and insulating Tape will act as a hinge. Remove 3 ribbon cable connectors from chassis and Carefully peel insulating tape from classic and leave connected to UI.
Fuse passes continuity test. No burn or dark spots on fuse glass. Next step is remove the battery board from the chassis.