6 1
B. TROUBLE SHOOTING OF REC MODE.
NO SOUND IN THE
PLAYBACK MODE
AFTER RECORDING
IS SIGNAL INPUT INTO
PIN 71,73 OF IY01.
IS 5V APPLIED TO PIN 76
OF IY01 AND IS ABOUT 5.7V
APPLIED TO PIN 2 OF TY01
CHECK A/V SELECT
CIRCUIT.
CHECK SYSCON.
IS THE VOLTAGE ABOVE 4V
AT PIN 80 OF IY01 ?
IS SIGNAL INPUT INTO PIN
79 OF IY01 ?
IS CLOCK AND DATA APPL-
IED TO PIN 63,64 OF IY01 ?
CHECK SYSCON.
CHECK RCY37, RCY38,
CCY27.
CHECK IY01.
DOES PIN 6 OF TY01
OSCILLATE ?
IS THE VOLTAGE FROM 0.7V
TO 3.0V AT PIN 5 OF IY01 ?
AC SIGNAL IS PUT ON THE
DC VOLTAGE AT PIN 5 OF
IY01.
CHECK AC HEAD.
IS THE VOLTAGE HIGHER THAN
3.0V AT COLLECTOR OF QCY06 ?
IS THE VOLTAGE FROM 0.7V
TO 0.8V AT PIN 6 OF IY01 ?
CHECK IY01.
CHECK QCY06
CHECK IY01.
AC SIGNAL PUT ON 70KHz
AT BASE OF QY04.
CLEAN HEAD.
CHECK RY21, RY22, TY01, CCY47.
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
NG
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
Summary of Contents for MV1421
Page 1: ...SERVICE MANUAL MV1421 1422 4822 34cm 48cm Televideo Effective December 1999 MV4822SERV ...
Page 6: ...4 3 BLOCK DIAGRAM 3 1 Audio Signal Flow ...
Page 7: ...5 3 2 Video Signal Flow ...
Page 8: ...6 3 3 TV and monitor power switching ...
Page 22: ...20 3 Block Diagram ...
Page 53: ......
Page 54: ......
Page 55: ......
Page 117: ...2 Main PCB Assy Circuit Diagram SECTION BEFORE AFTER MAIN TUNER ...
Page 118: ...3 SECTION BEFORE AFTER SUB TUNER ...
Page 125: ...10 Exploded View MV1421 model ...
Page 126: ...11 Exploded View MV1422 model ...
Page 127: ...12 Exploded View MV4822 model ...
Page 128: ...13 Exploded View DVT 20F9 model ...
Page 129: ...14 Exploded View DVT 21F1 model ...
Page 130: ...15 Exploded View DVT 21F2 model ...