Audio Systems: 2000 Lincoln Towncar Radio, lincoln towncar, radiio

Question
The buttons and controls on the front panel of the radiio will not "light-up" at night. I have been through the system, determining that the "lights" for the buttons are LEDs. When voltage is applied directly to the LEDs through a dropping resistor, all of them function properly. I presume that a (the) driver circuit(s) are at fault.

I have tried to obtain a schematic diagram and parts list so that I could continue troubleshooting the system but I can not locate them.

Do you have any leads as to the source of this problem (I understand it is quite common) or as to where I can obtain the schematics and parts list?

TRS

Answer
Tom,
Please give me the complete model number/s off the stereo. I will contact my sources to see if a service manual is available for this stereo. You may want to use a 12 volt test lamp and test to see if the panel/dash light supply to the stereo goes to 12 volts when the head lights are turned on. Check the supply line at the stereo connector.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net