Sharp VC-H982U

43
VC-A582U
VC-A582U(A)
VC-H982U
FLOW CHART NO.16 DRUM SERVO TROUBLESHOOTING
Drum servo does not function.
Check peripheral circuit of X701.
Is there 14.2MHz oscillation at pins (37) and (38) of IC701?
NO
In PB mode
YES
In REC mode
Is the drum FG signal at pin (65) of IC701 present?
Is the reference signal (V-SYNC) at pin (50) of IC701?
YES
NO
NO
Check composit-sync signal line. (C770-1, R770)
Check drum FG signal line.
Is the head switching pulse at pin (23) of IC701 present?
NO
See FLOW CHART NO.15. (HEAD SWITCHING PULSE TROUBLE SHOOTING.)
YES
YES
Is the drum error output at pin (33) of IC701.
NO
Replace IC701.
YES YES
Is th drum control voltage applied to pin (1) of ME connector?
NO NO
NO
Is pin (31) of IC701 in high impedance?
Check harness between AD and ME.
Replace IC701.
Replace drum motor.