Sharp VC-H992U, Service Manual

Page: 40 / 82

VC-H992U
VC-H992U(A)
40
FLOW CHART NO.6
Does the key switch make good contact, when the cassette tape is inserted?
Check switch contact.
Is there the function control voltage inputted at the pins(87) and (88) of IC701?
Check or place the peripheral circuit of IC701.
YES
YES
NO
Key-in input is not received.
FLOW CHART NO.8
A cassette tape is not take in.
YES YES
YES YES
NO
YES
NO NO
NO
NO
Check start sensor shutter.
Check line start sensor and all the way up thru to pin(79) of IC701. Check line pin(9) of IC701 and all the way up thru to pin(11) of IC706.
Check IC706.
Check between IC706 and loading motor.
Replace loading motor.
Is the specified voltage (about 10V) applied at the loading motor terminal when the cassette tape is inserted?
Does pin(13) of IC706 change to about 10V when the cassette tape is inserted?
Does pin(11) of IC706 go to a "H" (about 1.7V) level when the cassette tape is inserted?
Does pin(79) of IC701 change from "H" to "L" level when the cassette tape is inserted? Are start sensor shutter go to open when the cassette tape is inserted?
NO
NO NO
FLOW CHART NO.9
A cassette tape is taken in, but ejected at once.
Does the start sensor pulse at pin(79) of IC701 change from "L" to "H" level when the cassette tape is loaded?
Check start sensor and all the way up thru to IC701.
Does the end sensor pulse at pin(85) of IC701 change from "L" to "H" level when the cassette tape is loaded?
Check end sensor and all the way up thru to IC701.
Does the master cam mode shifter operate normally when the cassette tape is loaded?
Check cam switch and all the way up thru to IC701.
Replace IC701.
YES
YES YES
FLOW CHART NO.7
No operation is possible from the infrared remote control.
Operation is possible from the VCR, but no operation is possible from the infrared remote control. Is the supply voltage of 5V feed to pin(3) terminal of remote control receiver?
Check AT 5V lines.
Is "L" pulse sent out pin(1) terminal of receiver when the infrared remote control is activated?
Replace the remote control receiver or replace the remote control transmitter if necessary.
Is inputted "L" pulse to pin(5) of IC701?
Check line between at remote control receiver thru to pin(5) of IC701.
YES
YES
NO
NO
NO
YES
Replace IC701.
YES