Cof Damage; Crystal(Ctrl B/D: X2) Damage - Pioneer PDP-5016 Service Manual

3-4. COF Damage

(1) In case of shorting or opening the IC output of COF, it may
show one or several vertical lines.
Test Point: Enlarge the after measuring output TP of
O
COF~GND.
Wave format: As shown Output of (Fig. 7)
O
In case of normal wave output, when STB signal is
generated, maintain High output. And when STB signal
is generated again must be fall Low.
But when IC of COF is poor, STB signal is not generated
Output falls with Low.
(Fig. 7) When IC output of COF is poor
(2) In case of being damage IC of COF or power resistance,
the screen doesn't be shown or happens discharge partially.
Test Point: Enlarge the after measuring output TP of
O
COF~GND
Wave format: Output wave doesn't come out
O
<COF Normal Output Wave >
Measurance position: Enlarge the after measuring output
O
TP of COF (Full White Pattern)

3-5. Crystal(CTRL B/D: X2) damage

(1) When Crystal is damage, the screen doesn't be shown.
Test Point: Measuring 3pin of GND~Crystal(Ctrl B/D: X2)
O
Wave format: Output wave doesn't come out
O
(2) In case of unusual launch of the Crystal, it may blink the
screen.
Wave format: As shown (Fig. 8)
O
(Fig. 8) When Crystal is poor
<Crystal Normal Output Wave >
Measurance position: Measuring 3pin of Crystal(X2:
O
100MHz) (Full White Pattern)
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