Sharp VC-G200SM, Service Manual

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44
VC-G20SM/G200SM
VC-G201SM/G401SM
1
2
FLOW CHART NO.17 CAPST
AN SER
VO TROUBLESHOOTING
Capstan servo does not function.
Only PB mode inoperative
YES
Only REC mode inoperative
YES YES NO
YES
NO
NO
NO
NO
Check peripheral circuit of pin(50) of IC701, C716, C715 and R708.
Is there 14.318MHz oscillation at pins (37) and (38) of IC701?
Check peripheral circuit of X701.
YES YES
Dose pin(29) of IC701 operate normally?
Check "
1
"
Check "
2
"
Check capstan motor unit and/or replace.
Is there capstan AFC and
APC
at pins(31) and (33) of IC701?
Replace IC701.
Replace A/C head.
YES
YES
YES NO
NO
NO
Is there capstan AFC signal at pin (31) of IC701?
NO NO NO
Is there capstan APC signal at pin (33) of IC701?
YES NO
Replace IC701.
Does PB CTL signal appear at pin (76) of IC701?
Replace IC701.
Is there REC CTL signal output at pins(75) and (74) of IC701?
Does PB CTL signal appear at pin(76) of IC701?
Does A/C
head
operate normally? Adjust the height of the
A/C head.
Does the capstan FG signal appear at pin (67) of IC- 701?
Check the capstan FG signal line bet- ween pin(1) of P701 and pin(67) of IC701.
Check peripheral circuit of P701.
Is the V
-SYNC
signal(reference) at pin(50) of IC701?
Are REC and/or PB mode inoperative?
NO