Osd Circuit - Zenith XBR411 Manual

VCR ELECTRICAL TROUBLESHOOTING GUIDE
2. SERVO CIRCUIT
(4) Keys do not work
Keys do not work
Is 5V applied to IC501
Pin78?
YES
Does FLD change when
a function button is
pressed?

4. OSD CIRCUIT

(1) I 2 C BUS CHECK
No I 2 C bus communication
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".
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