Sharp XA-905, Service Manual, Page: 43 / 79

43
XA-905
XA-920
1
2
FLOW CHART NO.17
Capstan servo does not function.
Only PB mode inoperative
YES
Only REC mode inoperative
YES YES NO
YES
NO
NO
NO
NO
NO YES
Check peripheral circuit of pin(50) of IC701, C770, C771 and R770.
Is there 14.318MHz oscillation at pins (37) and (38) of IC701?
Check peripheral circuit of X701.
YES YES
Does 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(6) of AC connector and pin (67) of IC701.
Check peripheral circuit of AC connector.
Is the V-SYNC signal(reference) at pin(50) of IC701?
Are REC and/or PB mode inoperative?