I did the modifacations for the 9950/990 heads to enable program change from the front of the head! Everything goes good untill I go to exit program mode. The instructions say to squelch up to change mode and to sqelch down to reset and write the EPROM. My head is doing the opposite and fails to change the EPROM. I have checked for shorts and all anything else that I can think of, any ideas what is going wrong?
Bob KC0FMI