Service manual

46
DV-NC55U/C/M
FLOW CHART NO.12
Is there 14.3MHz oscillation at pins(37) and (38) of IC1701?
Check peripheral circuit of X1701.
Is there drum FG signal at pin(65) of IC1701 present?
Is the V-SYNC signal(reference) at pin(50) of IC1701?
NO
YES
In PB mode
YES
In REC mode
Is the head switching pulse at pin(23) of IC1701 present?
See FLOW CHART NO.11 <No head switching pulse>
NO
YES NO
Is the drum APC output at pin(34) of IC1701 and drum AFC output at pin(32) of IC1701 present?
Replace IC1701.
NO
YES
Is the drum control voltage applied to pin(2) of IC1706?
Is pin(46) of IC1701 in high impedance?
NO
YES
Does the IC1706 operate normally?
YES
Replace drum motor.
YES
Drum servo does not function.
Check peripheral circuit of C1770-1 and R1770.
NO
Check drum FG signal line.
FLOW CHART NO.13
2Only REC mode inoperative
YES
NO
NO
YES
YES
YES
NO
YES
NO
NO
YES YES
YES
NO
NO
YES
NO
NO
YES
YES
NO
Are REC and/or PB mode inoperative?
Check peripheral circuit of X1701.
1Only PB mode inoperative
Does PB CTL signal appear at pin(76) of IC1701 (TP1201)?
Does AA-MH harness normally?
Does A/C head operate normally?
Replace A/C head.
Check AC-MC connector and capstan FG signal line.
Check capstan motor unit and/or replace.
Is there capstan AFC and APC at pins(31) and (33) of IC1701?
Replace IC1701.
Replace AA-MH harness.
Readjust the A/C head height.
Is there 14.3MHz oscillation at pins(37) and (38) of IC1701?
Does the capstan FG signal appear at pin(67) of IC1701?
Dose pin(29) of IC1701 operate normally?
Check "1"
Check "2"
Replace IC1701.
Is there REC CTL signal output at pins(75) and (74) of IC1701? Is the V-SYNC signal(reference) at pin(50) of IC1701?
Check peripheral circuit of C1770-1 and R1770.
Is there capstan AFC and APC at pins(31) and (33) of IC1701?
Capstan servo does not function.
FLOW CHART NO.14
NO
YES
YES
NO
YES
NO
YES NO
YES
NO
NO
NO
NO
YES YES
Is picture signal input into pins(30), (28) and (31) of IC1201?
Is picture signal output to the pin(52) of IC1201?
Is picture signal input into the pin(49) of IC1701?
Check the line between pin(52) of IC1201 and pin(49) of IC1701.
Is 5V applied to the pin(12) of IC1201?
Check the YC 5V line.
1 External input mode • Check the line between the rear video input terminal and pin(30) of IC1201. • Check the line between the rear video input terminal and pin(28) of IC1201. 2 U/V tuner mode Check the line between the pin(25) of U/V tuner and pin(31) of IC1201.
Is picture signal output to the pin(47) of IC1701 ?
Is 5V applied to the pin(51) of IC1701?
Check the AT 5V line.
Is picture signal output to the emitter of video output buffer (Q1251)?
Line output: Is there V-SYNC signal input at pin(6) of IC2003.
Check the line between pins(63) and (62) of IC1201 and pins(56) and (57) of IC1701.
Check Q1251 periphery.
NO
Check the line between the Q1251 emitter and the pin(6) of IC2003.
Is there V-SYNC signal output at pin(2) of IC2003.
YES NO
Check the VIDEO OUT terminal (J1202) and the line between the pin(2) of IC2003 and the VIDEO OUT terminal (J1202).
YES YES
Are the pin(1) of IC2003 on "L" level?
Replace IC2003.
NO
Check the DVD-H line.
NO
Is 5V applied to the pin(3) of IC2003.
Check the PC 5V line.
RF output: Check Q1251 periphery and tuner pin(6) periphery.
Is serial data clock signal applied to the pins(63) and (62) of IC1201?
Picture E-E does not appear.