Rf/Servo Circuit - Zenith D35 Service Manual

3. RF/Servo Circuit

A.
CHECK POINT(General)
Does signal goes
"High" to IC201 Pin186 when the
power is on?
YES
Does signal pulse
input to IC201 Pins53, 54 when
the power is on?
YES
Does
TTL pulse output to
IC201 Pin156?
YES
Is IC201
Pins79, 80, 84, 88 voltage
about 2.2V?
YES
END
NO
NO
Check "2.µ-COM Part".
NO
33.8688MHz clock input
to IC201 Pin59?
YES
Replace IC201
(IC206 soldering or IC defect).
NO
Check power circuit.
Does
NO
3-60
Replace X201 or IC206
(33MHz clock defect)