Sharp 13VT-K100 - Capstan Servo Troubleshooting Flowchart

13VT-K100/150
13VT-CK10
47
NO
NO
NO
NO
NO
NO NO
NO
CAPSTAN SERVO TROUBLESHOOTING FLOW CHART NO.1-11
YES YES
YES
YES
NO
NO
YES YES YES
YES
YES
YES YES YES
NO
Is pin (75) of IC7701 normal?
Replace the capstan motor.
Replace IC7701. Replace IC7701.
Replace the FFC AA-MH.
Check X7701, C7705 and C7706.
Check the capstan FG signal line between AM connector and IC7701.
Does there appear the capstan FG signal at pin (85) of IC7701? Is there the capstan control voltage applied to pin (4) of AC connector?
Check the composite sync. signal at pin (14) of IC2201, Q2201 and Q2202, up to pin (84) of IC7701.
Replace IC7701.
Replace A/C head.
Check " A " Check " B "
In case of NO GOOD
Does there appear the V-sync. at pin (84) at IC7701?
Is there REC CTL signal output at pins (92), (91) of IC7701?
Is there capstan control signal at pin (77) of IC7701?
Are REC and /or PB mode inoperative?
Is the FFC AA-MH normal? Does the A/C head operate normally?
Adjust the height of the A/C head.
Does PB CTL signal appear at pin (97) of IC7701?
Does CTL amplifier circuit of IC7701 (pins (92) to (97)) operate normally? (Does the noise appear at pin (97) when touch R7774 by hand?)
Only PB mode inoperetive. Only REC mode inoperetive.
A
B
Is there 16MHz oscillation at pins (38) and (39) of IC7701.
Capstan servo does not function.