16
Model No: 21HAP1BE
Version 1.0
b. No
sound
In this kind of failure, first of all we should observe if there is the picture on the CRT. It proves the small signal circuit to work correctly with the picture on the CRT and we only check the sound signal processing and sound
amplification circuit. The repairing method (B1) may be referred without picture. The detail checking and repairing steps are as follow.
Note: Before repairing, assure that the volume is on and the state of set is in “TV”.
5V
YES
YES
NO
NO
8V
YES
NO
YES
YES
YES
NO
Hear if there is the voice liking “Ka…Ka ” in the loudspeaker via using “ Signal-input way ” by touching pin 7 of N301
Check C367,R369,V395,N301
Hear if there is the voice liking “Ka…Ka ” in the loudspeaker via using “ Signal-input way ” by touching pin 3 of N121
Hear if there is the voice liking “Ka…Ka ” in the loudspeaker via using “ Signal-input way ” by touching pin 44 of N301
Check R733, C732, N301
Check R126,N505, N121
The voltage on pin 9,10of N121
Check 8V-power supply
Hear if there is the voice liking “Ka…Ka ” in the loudspeaker via using “ Signal-input way ” by touching pin 2,10 of N701
Check VD521,R165,C522,T501,N161
The voltage on pin 16 of N121
Hear if there is the voice liking “Ka…Ka ” in the loudspeaker via using “ Signal-input way ” by touching pin 13 of N121
Check R157,C157,N161
Hear if there is the voice liking “Ka…Ka ” in the loudspeaker via using “ Signal-input way ” by touching pin 6,8of N161
The voltage on pin 1 of N701
Check R153,C153,R154,C154,N121
Check C157,C153, N101
Check SP161, SP162, N161
NO
8V
8V
12.5V
NO
