2001 740i. LOST Multifunction display

2001 740i. New with the E38/740i car.
I lose my NAV/Radio/Multifunction display after disconnecting my battery for replacing the oil cover gasket.
When I reconnected the battery back, my display was blank. I called for help. Helper is not familiar with BMW. I could not started my car b/c I set the security code. After reading the manual, I could start my car again but still no display. Radio only works for ~3 min then stops.
1. Any thing I can do to bring back the multifunction display back? (the back light does work)
2. Do I need to take to dealer to fix it? or just any simple fuse or reset somewhere in the car that I could do?

Any help is greatly appreciated. Many thanks in advance.

bmw2qnj2le

Try disconnecting your batt again. Leave it disco'd for about 20mins or so. When you disco the batt make sure you disco the negitive...not the positive. Reconnect and report back.

Also try both terminal disconnect and joint them (NOT THE BATTERY TERMINALS) together. Resets a lot of stuff and might be a quick fix.

Today 24 Dec 2012, I disconnect both positive and negative terminals and check the 2 fuses (27 & 47). They are not blown. I check them with an ohmmeter. After terminals are connected, the mutli function display is still blank! The back light is on because I check when the outside is dark. Does the multi function display device have its own fuse? the radio only plays for 2-3 mins then stops but I can change stations. It does hinder the operation of the car. The nav system and 6 cd charger in the trunk do work. Any help is greatly appreciated.