Can anyone help me identify and find a schematic of this 4 wire module with the markings as follows:
428502 REV.AD
EMD MEX
991501

I believe it might be an analog line hold module.

 

Someone here thinks it is an "EL driver":
http://www.stratusphere.net/forums/index.php?/topic/34987-illuminant-for-prnd3l/

It seems that the poster, need4speed, means an EL backlight inverter.

 

well thats not even close..
Did this phone have a display/illumination on it of some sorts?

 

well thats not even close..

I can't argue that. I guess I should have been more tentative about the post I linked to.