Update: HELP!!!
Ok, my independent shop passed my complete Command 2.5 unit to a local Car Audio shop that the local MB Dealership uses from time to time.
They confirmed that the Command unit would not power up.
They switched the "power supply" box of the unit with one out of another unit they had with a cracked screen and it powered on on their bench.
EDIT: This turned out to NOT be a good idea on the part of the Audio Shop. (More later...)
Then they installed it in the car...
The NAV system powers on.
The keyless entry remotes now work! (Nobody knows how these were related.)
The CD changer was dead, but now the audio shop says it goes crazy, won't settle down and needs replacing.
The audio shop says the main audio amplifier module in the trunk is dead and needs to be replaced along with the CD player.
Presently, both the CD player and the Audio Amp are out while he searches for replacements.
At this time:
The radio appears to be playing, when selected, but without sound.
The NAV system WILL NOT display a MAP of my present location.
It displays a screen with an hour glass, the GEO CODE LOCATION at the top of the screen and it NAMES the STREET I am on across the bottom.
JUST NO MAP!
UPDATE:
My independent MB shop thought it unlikely that the audio amplifier was bad so I picked up the amp and the CD player from the Audio Shop. They reinstalled them and ran the diagnostics. The Command unit sees the audio amp as well as the CD player, but the telephone controller unit (Voice Command) is not responding. He is hoping to find a way to bypass this controller because it is an old analog unit and serves no purpose. It is believed that this device is suppressing the audio.
EDIT: Wrong... My car doesn't have the Voice Command unit. That was normal, but he did bypass the phone unit. It was an Analog unit and is of no use anyway...
They will continue on it tomorrow...