Osd Circuit - Zenith XBV613 - DVD/VCR Combination Service Manual

2. SERVO CIRCUIT
(4) KEY doesn't working
KEY doesn't working.
Is 5V applied to IC501
Pin99?
YES
Does LED or FLD change
when a function button is
pressed?

4. OSD CIRCUIT

(1) No OSD display.
No OSD or F.OSD display.
Is 5.3V applied to
IC501 Pin53?
YES
Does oscillation occur at
IC501 Pins44, 45?
YES
Replace IC501.
(2) I 2 C BUS CHECK
The I 2 C waves don't
come out.
Does Power appear at the
Pull up impedence
(R569, R507)?
YES
Replace IC501.
NO
Refer to "SMPS 5.3VA
Trouble Shooting".
NO
Replace the defective
switches.
NO
Refer to "SMPS 5.3VA
Trouble Shooting".
Check or Replace the phe-
NO
ripheral Circurity.(L511,
R518, C596, C595)
NO Refer to "SMPS 5.3VA
Trouble Shooting".
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