Pioneer PDP-5016 Service Manual page 61

3-3. SCAN IC(Y drv B/D: IC1~12) Damage
(1) In case of SCAN IC poor, one horizontal line may open at
screen.
Test Point: GND ~ Output ICT measurance of Y drive B/D
O
Wave format: As shown (Fig. 4)
O
(Fig. 4) When SCAN IC is poor
(2) Screen may not shown when SCAN IC is damaged by
external electricity or spark.
Test Point: GND ~ Output ICT measurance of Y drive B/D
O
Wave format: Output wave format isn't output (You can
O
see the damage for SCAN IC)
(3) Screen shaked horizontally when Y drv B/D Top and
Bottom cable is poor
Test Point: GND ~ Output ICT measurance of Y drive B/D
O
Wave format: As shown (Fig. 5)
O
(Fig. 5) When occurance the Scan Noise
(4) In case of shorting the SCAN IC output by a dust, foreign
substance, it may overlap two horizontal lines on screen.
Test Point: GND ~ Output ICT measurance of Y drive B/D
O
Wave format: As shown (Fig. 6)
O
Normal Wave
Measurance position: Output ICT of Y drive B/D
O
SCAN section enlarge (Full White Pattern)
- 15 -
Widen the Pulse width
100V
60V
Decrease in voltage of
Break the SCAN Pulse
SCAN Pulse
(Fig. 6) When SCAN IC output is short
SCAN Section
<SCAN IC Normal Output Wave >