Grundig GV 900 SV/1 Manuel De Service page 44

Troubleshooting Diagram 11 – Head Servo
Head Servo Error
14.318MHz oscillation
at IC701-(37, 38)?
in PB mode
FG signal at IC701-(65)?
YES
Head switching pulse at NO See Troubleshooting Diagram 10
IC701-(23)?
– Head Switching Pulse
YES
NO
APC signal at IC701-(34)?
IC701?
AFC signal at IC701-(32)?
YES
NO
Head motor control voltage
Low level at IC701-(58)?
at IC702-(29)?
YES
Signal path between
IC702?
IC701-(34, 32) and
IC702-(29)?
Signal path between IC702
and connector AD, flexprint
lead, headwheel motor?
Troubleshooting Diagram 12 – Capstan Servo
Capstan Servo does not work
PB mode
Are REC and/or PB
inoperative
mode inoperative?
14.318MHz
YES
oscillation
at IC701-(37, 38)?
NO
Peripheral circuit of
X703?
YES
PB CTL signal
at IC701-(76)?
NO
A/C head?
Height adjustment
of A/C head?
englisch • English • anglais
NO
X703, C756, C757, IC701?
YES
in REC mode
YES
V-SYNC signal (reference)
at IC701-(50)?
NO
Peripheral circuit of
IC701-(50), C746, C747
and R745?
YES
NO
REC mode
inoperative
V-SYNC signal Peripheral circuit of
NO
(reference) at IC701-(50), C746,
IC701-(50)? C747 and R745?
YES
REC CTL signal
NO
at output
IC701?
IC701-(75, 74)?
YES
Capstan AFC and
NO
NO
APC signal at
IC701-(31, 33)?
Control voltage at
YES IC701-(59)?
YES
Capstan FG signal
at plug contact Power supplies
NO
AC-(6) / M12V/20V, PC5V?
IC701-(67)?
Capstan motor?
Troubleshooting Diagram 13 – Loop-through (E-to-E) Mode
No Picture Signal
in E-to-E Mode
Picture signal at input
IC201-(28, 30 or 31)?
YES
Picture signal at output
IC201-(52)?
YES
NO
Signal path between Picture signal at
IC201-(52) and IC701-(49)? IC701-(49)?
YES
IC701?
YES
Picture signal at
NO
5V at IC701-(51)?
IC701-(47)?
YES
NO
Check PC 5V power Picture signal at
Q708-(E)?
supply.
YES
Picture signal at tuner Picture signal at Q2801?
contact 6? (only for 1 Euro-AV socket)
Picture signal at contact 19 of Euro-AV1 socket?
Check signal paths:
– IC201-(28): from video input socket on the front?
– IC201-(30): from Euro-AV1 socket
NO
(only for 1 Euro-AV socket)
– IC201-(31): from tuner or Euro-AV1 / 2 sockets
(only for 2 Euro-AV sockets)
NO PC5V power supply?
NO
5V at IC201-(12)?
YES
Signal paths between
NO
Data and clock signal
IC701(56, 57) and
at IC201-(63, 62)?
IC201-(63, 62)?
YES
IC201?
Picture signal at
IC2501-(19)?
(only for 2 Euro-AV sockets)
Picture signal at
IC2501-(20)?
IC201
IC202
IC651
IC701
IC702
IC703
IC704
IC705
IC801
IC901
IC902
IC1601
IC1602
IC1701
IC1801
IC1901
IC1951
IC2501
IC5301
IC6301
RMC801 4-21
Tuner
S. / P.
4-26
4-26
4-25
4-22
4-21
4-22
4-22
4-22
4-21
4-28
4-28
4-33
4-29
4-36
4-22
4-35
4-35
4-24
4-31
4-24
4-30