U3990F6 U3990F6 BT_CK 1 18 BEEP/TEST AV_CK 2 17 TP_CK LED_L NC 3 16 OSC1 4 GND 5 15 14 VDD LED_T 6 13 OUTB FAN 7 12 LED_P 8 11 PROT OUTA RS_CK 9 10 IF_IN OSC2 -1- U3990F6 OUTA OUTB OUTG -2- U3990F6 +5V BEEP/TEST -3- U3990F6 -4-