Service manual

44
DV-NC55U/C/M
FLOW CHART NO.1
Is the supply voltage of 5V feed to pin(8) of IC5101?
Check STBY 5V line.
Is the supply voltage of –20V feed to pin(1) of IC5101?
Check STBY –20V line.
Is it possible to confirm signals FIP CS, FIP OE, FIP DATA, and FIP CLK on the pins(2), (3), (5) and (6) of IC5101?
Check signal line between IC1701 and IC5101.
Are grid and segment signals supplied to the indication tube (DG5101) from the indication tube driver IC (IC5101)?
Replace IC5101.
FLOW CHART NO.2
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 IC1701?
Is supply filament voltage feed between pin(1)/(2) and (31)/(32) of the flourescent display tube?
Check power circuit and D1952.
Check the periphery of fluorescent indication tube and main block.
Check that the fluorescent indication tube is free from damages such as crack.
NO
NO NO
NO NO NO
NO
YES YES
YES YES
YES
YES
Check or place the peripheral circuit of IC1701.
YES
The VTR flourescent display tube fails light up.
Key-in input is not received.
FLOW CHART NO.3
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 IC1701?
Check line between at remote control receiver thru to pin(5) of IC1701.
Replace IC1701.
NO
NO NO
YES
YES YES YES
No operation is possible from the infrared remote control.
FLOW CHART NO.5
Does the start sensor pulse at pin(79) of IC1701 change from "L" to "H" level when the cassette tape is loaded?
Check line start sensor and all the way up thru to pin(79) of IC1701.
Does the end sensor pulse at pin(85) of IC1701 change from "L" to "H" level when the cassette tape is loaded?
Check line end sensor and all the way up thru to pin(85) of IC1701.
Does the master cam mode shifteroperate normally when the cassette tape is loaded?
Check cam switch (A), (B) and all the way up thru to pins(7), (6) of IC1701.
Replace IC1701.
NO
NO NO
YES YES
YES
A cassette tape is taken in, but ejected at once.
(VTR)
FLOW CHART NO.4
Is "L" level applied at pin(93) of IC1701.
Are start sensor shutter go to openwhen the cassette tape is inserted?
Check start sensor shutter.
Does pin(79) of IC1701 change from "H" to "L" level when the cassette tape is inserted?
Check line start sensor and all the way up thru to pin(79) of IC1701.
NO
NO
YES YES YES
Does pin(11) of IC1706 go to a "H"(about 4.7V) level when the cassette tape is inserted?
Check line pin(91) of IC1701 and all the way up thru to pin(11) of IC1706.
NO
YES
Does pin(13) of IC1706 change to about 10V when the cassette tape is inserted?
Check IC1706.
NO
YES
Is the specified voltage (about 10V) applied at the loading motor terminal when the cassette tape is inserted?
Check between IC1706 and loading motor.
NO
YES
Replace loading motor.
Check R1847.
NO
A cassette tape is not take in.