Samsung DLP HLN507WX/XAA, lamp and color wheel recently replaced. After 2 months lost picture with just horiz. lines. Ordered complete service manual and determined that it was the digital board. Digital bd in set was AA41-00851A this bd was not available from DM, but 2yr later upgraded digital bd AA41-00851B. From all physical aspects it is almost identical. When place in set it gave very good picture but no Audio as tho it is muted. Old bd Audio is OK. Audio mute line on digital bd comes from pin 49 of IC328 (flash memory) and goes out on pin21 of plug cn307 to the analog bd. This line is same on both versions. Mute ind can be switched on and off on the screen but will not give audio. Ic328 is controlled by Ic327 processor. Today I will verify hi-lo status of this audio mute line on each bd. ANY solutions would be greatly appreciated . GET TECHNICAL as I can understand after 45 yrs in this industry. thank you.