Over the weekend I took the radio apart to clean the volume control. I managed to get to the potentimeter buy cutting through the side of the case with a dremel. Then I bent back the little metal strap that covered a small hole in the side of the pot. Shot some contact/pc board cleaner into this hole while spinning the pot several times. I reinstalled the radio and the crackling was now gone. Unfortunately the LCD display was hardly visable. After resoldering the board and reinstalling the radio I still had the same problem. Took the radio back out removed the LCD display board and resoldered the board but still no success. Finally I unsoldered the LCD bracket and removed the LCD display. This is when I found out that the LCD is not hardwired to the circuit board. The LCD has a rubber strip that makes contact with the circuit board through pressure. Dang dus thing I have ever seen. I cleaned the contact points and reassembled the LCD. Put it all back together and now it works fine. My question is ...Is there some kind of goop that should be applied to the rubberstrip before I reinstalled or is this a dry fit?
As you noticed, any dirt and film on the strip contacts will impede good contact. It would be best to not apply any kind of substance (dielectric grease?) to it in order to avoid the potential loss of good conduction between the circuit board and the LCD. Just my $.02