BMW Repair: 2001 740 Battery Replace - Navigation failure, cassette works, nav computer

Question
Greetings - I replaced the battery in our 2001 740. Hooked up my little lead acid jumper/starter under the hood so I didn't have everything reset. Now the navigation/info center is dead but the backlighting is working. The display will go from black with the key off to slightly lighter with the key on. Radio/cassette works for a few minutes and then shuts down. Checked fuses that pertain to the nav system.  Can't see what's going on with the display to see if any of the other functions are working.  The cassette open/close works fine. I noticed the red light on the CD ROM in the trunk is/was flashing after the battery install.  Is there a master reset for this system or a cold start procedure for lose of power?  The only time that +12v power may have drooped is when the engine wouldn't try to start.
thanks
Rich

Answer
Rich, is the red led on the NAV still on with the car? Remove the unit and check the fuse in the back of the unit. If fuse is good and led is still not on then the NAV computer may be at fault. (not cheap usually $2000.00 USD) You may want to have it diagnosed before shelling out that kind of cash. Or try swapping another Nav. unit from another car. Wait a couple minutes before disconnecting power to Nav.(wait till the led goes out after key off).
-Evan