My Sansui 5000A has FM issue while all other functions work fine. The 5000A picks up FM stations fine but no FM when I press "FM Stereo only", depress that button then FM is back but volume is low (only 50% compared to other inputs). The tuning meters do not work either. While on AM mode, it has loud cracking noise when tuning among the stations but at least it works. Please help me to track down the issue or where to look at. FYI, I got 12V at F-1219 board as stated in schematic. Thanks a lot.