21HF2-SS
5 – 2
TROUBLE SHOOTING FLOW CHART (Continued)
NO PICTURE, NO SOUND
Does signal appear at pin
(2) of IC301 ?
NO SOUND
No snow noise.
Does noise or signal appear at pin (41)
of IC801 ?
Noise increases but no signal is
received.
Check the tuner supply voltage LB must
approx. 5V. BT must be approx. 33V.
And check the CH preset data.
Check the tuner AGC at
TP201.
Does noise or
signal appear at
pin (58) of IC801 ?
Check IC801 and
related circuit.
Check pin (60) at
IC801 and related
circuit.
Check pin (1) of
SF201, Tuner and
related circuit.
Check pin (60) at
IC801 and related
circuit.
Check pin (59) of
IC801, Tuner and
related circuit.
Check pin(58) of
IC801.
Does the noise level increase at max.
Contrast, Brightness and Sound controls ?
CIRCUITS TO BE CHECKED:
Tuner.
PIF.
Automatic Gain Control.
(5V), (32V) Power Source.
CIRCUITS TO BE CHECKED:
Sound Detector Circuit.
Sound Switch and Att.
Control.
Audio Output Circuit.
Check TV sound from pin (54)
of IC801 and IC301 peripheral
circuit.
Check Speaker.
Does noise or
signal appear at
pin (63) and (64)
of IC801 ?
Содержание 21HF2-SS
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