76
Keypad
function
1.chk U1 voltage source(5V)
2.chk U1 output signal (always 5Vdc in regular time,no pulse voltage)
Yes
Yes
No
No
No
Rear Front IR
function
FAN/BD
Fan control:
1.chk the voltage of QF1 (5,6 ,7,8 )
2.chk the fan voltage U502(2,15),U503(8)
3.check Y501(32.768kHz)
No 5V
1.Check Q701 & thermal Breaker
LED dark
1.chk LED voltage from J1
2.chk the mounting direction of LEDs
No work
1.chk buttons con ta ct to P C B