Scan Ic(Y Drv B/D: Ic1~8) Damage - Hitachi SM0063 Service Manual

3-3. SCAN IC(Y drv B/D: IC1~8) damage

(1) In case of SCAN IC poor, one horizontal line may open at
screen.
Test Point: ICT measurance of GND~Y drive B/D output
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
SCAN IC poor, external electricity or spark.
Test Point: ICT measurance of GND~Y drive B/D output
O
Wave format: Output wave format isn't output (You can
O
see the damage for Y drive B/D Top or Bottom's SCAN
IC)
(3) Screen shaked horizontally when Y drv B/D Top and
Bottom cable is poor
Test Point: ICT measurance of GND~Y drive B/D output
O
Wave format: As shown (Fig. 5)
O
(Fig. 5) When Y drv B/D Top and Bottom cable is poor
(4) In case of shorting the SCAN IC output by a dust, foreign
substance, it may overlap two horizontal lines on screen.
Test Point: ICT measurance of GND~Y drive B/D output
O
Wave format: As shown (Fig. 6)
O
(Fig. 6) When SCAN IC output is short
<SCAN IC Normal Output Wave >
Measurance position: SCAN section enlarge the after
O
measuring output ICT of Y drive B/D. (Full White
Pattern)
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