Grundig GV 900 SV/1 Manuel De Service page 43

Troubleshooting Diagram 7 – Capstan Motor
Capstan Motor does not run.
NO
2.5V at IC701-(69)?
YES
NO
>2.6V at IC701-(59)?
YES
NO
5V at plug contact AC-(8)?
YES
NO
Signal path between IC701-(59) and
>2.6V at plug contact AC-(4)?
YES
NO
Signal path between IC701-(60)
1.6...2.7V at plug contact AC-(3)?
YES
NO
12V or 20V at
(Q9903, Q9904, Q9909, Q9910)?
plug contact AC-(5)?
YES
Capstan motor?
Troubleshooting Diagram 8 – Headwheel Motor 1
Headwheel Motor does not run.
NO
>2.5V at IC701-(69)?
YES
NO
>2.6V at IC701-(58)?
YES
NO
5V at IC702-(2, 25)?
YES
NO
>2.6V at IC702-(29)?
YES
NO
12V at IC702-(20)?
YES
IC702, signal path between
IC702 and connector AD, flexprint
lead, headwheel motor?
C728, C729, IC701?
IC701?
Power supply PC 5V?
plug contact AC-(4)?
and plug contact AC-(3), IC701?
Power supply M12V/20V
C728, C729, IC701?
IC701?
Power supply STBY5V?
Signal path between
IC701-(9) and IC702-(2)?
Signal path between IC701-(58)
and IC702-(29), IC701?
Power supply M 12V?
englisch • English • anglais
Troubleshooting Diagram 9 – Headwheel Motor 2
Headwheel Motor runs only
for a few seconds.
NO
PG signal at IC702-(8)? Peripheral circuit of IC702-(4...7)?
YES
NO
PG signal at IC701-(66)?
YES
Head switching pulse at IC701-(23)?
IC701?
Troubleshooting Diagram 10 – Head Switching Pulse
No Head Switching Pulse
V-H.SW.P at IC701-(23).
See Troubleshooting Diagrams 8, 9
NO
Is the headwheel rotating?
YES
YES
PG and FG signals at
IC701-(66, 65)?
NO
FG signal
ca. 5Vpp
PG signal
ca. 5Vpp
YES
PG and FG signals at
IC702-(8, 9)?
NO
IC702?
IC702?
NO
YES
Headwheel motor?
Signal path between IC702-(8)
and IC701-(66)?
IC201
IC202
– Headwheel Motor 1, 2
IC651
IC701
IC701?
IC702
IC703
IC704
IC705
IC801
IC901
IC902
IC1601
IC1602
IC1701
IC1801
IC1901
Signal path between IC702 and
IC1951
IC701?
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