FUNAI DRVR-B778S Service Manual page 37

3 VCR Section
FLOW CHART NO.1
The key operation is not functioning.
Are the contact point and the installation state of
the key switches normal?
Is the control voltage normally inputted into
Pin(7) of IC501?
Replace IC501.
FLOW CHART NO.2
No VCR operation is possible from the remote control unit. (Operation is possible from the unit.)
Is 5V voltage supplied to the Pin(3) terminal of
the RM1501 (remote control receiver)?
Is the "L" pulse sent out from Pin(1) terminal of
the RM1501 (remote control receiver) when the
remote control unit is activated?
Is the "L" pulse signal supplied to Pin(14) of IC501?
Replace IC501.
Yes
Yes
Yes
Yes
Yes
No
Re-install some key switches correctly or
replace some key switches.
No
Check the key switches and their periphery, and
service it if defective.
Terminal voltage of IC501-7
4.30
3.60
2.90
2.39
1.98
1.61
1.27
0.92
0.51
(V)
No
Check AL+5V line and service it if defective.
No
Replace the RM1501 (remote control receiver).
Replace remote control unit if need.
No
Check the line between the RM1501 (remote
control receiver) and Pin(14) of IC501, and
service it if defective.
1-11-13
KEY-1
IC501-7
CH
DOWN
CH UP
OUTPUT
SELECT
REC
/OTR
FF
REW
PLAY
STOP
/EJECT
POWER
E9G01TR