Deflection Board Troubleshooting Chart - Zenith ZCM-1490 Service Manual

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APPLY INPUT (USE FILL
SCREEN TESl) AND
~
TURN MONITOR ON.
DISPLAY ON?
!NO
TEST SCREEN WITH
HAND FOR STATIC
ELECTRICITY,IF
AB?ENT, CHECK HIGH
VOLTAGE CIRCUITS. IF
PRESENT, CONTINUE
THROUGH CHART.
VERTICAL
DEFLECTION
PRESENT?
JNO
CHECK IC2101,
PIN 1. OK?
i1l
!NO
CHECK IC2101,
PINS. OK?
"1J
!NO
CHECK IC2101,
PIN 1. OK?
[,l
!NO
THIS CHART CAN ONLY ASSIST IN DIAGNOSING FAULTY CIRCUIT AREAS BY
SYMPTOM. WAVEFORM MEASUREMENTS CANNOT BE MADE SAFELY WHILE THE
MONITOR IS ON. TO BE SERVICED, THIS BOARD MUST BE REMOVED FROM THE
MONITOR. USE THE RESISTANCE MEASUREMENT TABLES TO IDENTIFY FAULTY
COMPONENTS AFTER A FAULTY CIRCUIT AREA IS IDENTIFIED.
HORIZONTAL HIGH VOLTAGE
YES
DEFLECTION YES PRESENT? TEST
PRESENT? SCREEN WITH
!NO
HAND FOR STATIC
ELECTRICITY •
~NO
SUSPECT VERT. VERIFY PROPER
~
DEFLECTION SYNC INPUT IS
@
AMPLIFIER, PRESENT
SUSPECT HIGH VOLTAGE
0210112108,02106
~
COMPONENTS LIKELY TO
BE STRESSED: 03203
03202; CHECK TP3
®;
SUSPECT COMPONENTS
SHUTDOWN CIRCUIT AND
~
SUSPECT IC2101
LIKELY TO BE STRESSED:
~208
@
03003, CR3003 IN
HORIZONTAL OUTPUT
STAGE. ALSO SUSPECT
HORIZONTAL
VERIFY PROPER
PROCESSOR IC3401.
NOTES
~
SYNC INPUT IS
DISPLAY
ADJUSTMENTS
OK?
~NO
PERFORM
APPROPRIATE
ADJUSTMENTS AS
DETAILED IN
CHAPTER 4.
@
PRESENT.
!
1. IC2101 PINS CAN BE ACCESSED
THROUGH A SLOT IN THE LOWER RIGHT
SUSPECT HIGH VOLTAGE
PORTION OF THE PANEL HOLDING THE
SHUTDOWN CIRCUIT; IT
DEFLECTION BOARD. SEE THE
SUSPECT IC2101, MAY DISABLE
COMPONENT VIEW FOR LOCATION.
02110, VERTICAL HORIZONTAL SYNC TO
OSCILLATOR, SIZE, HORIZONTAL
2. TP3 CAN BE ACCESSED THROUGH A
OR DRIVER DEFLECTION AMPLIFIER
MARKED HOLE IN THE PANEL HOLDING
STAGES WHEN ACTIVATED.
THE DEFLECTION BOARD.
Figure 6-5. Deflection Board Troubleshooting Chart