47
105S2 CM23 GSIII
Repair flow chart
a pin3 compare the level with pin 4
b. pin4 generate the saw_tooth wave
c. pin5 controlled output duty
d. pin6 pwm output to control B+
F. TDA4857
Check List
Basic check
Vcc > 9V
during startup
11.EWDRV
8. HDRV
14,15 Vsync,Hsync
12,13 Vout1/Vout2
inhibit pin6 output
if pin3 is low
pin17 = Hunlock = floating
pin30 = Hpll2 = 0V
pin6 = HDRV = floating
pin8 = BDRV = flaoating
pin12 = Vout1 = floating
pin13 = Vout2 = floating
pin16 = CLBL= Hi
if active
pin16 / 17
CLBL=hi
HUNLOCK = hi
if no exist
3.4.5.6 B+ control
2. Xray
( from LOT )
1. HFLB
( from H.defl )
to H_deflection.
7605 base
Vcc =pin9=pin10=12V
gnd =pin7=pin25=0V
pin16 is pulled up to high level at conditions
1.pin30 = softstart pll2 = 0V
2.pin26 = pll1 is unlock in searching mode
3.pin1 = HFLB no exist
4.pin2 = Xray once actived
5.pin10 = Vcc < 9V
16. CLBL
to H-deflection east/west control
7612 base
differential input
to 7401 pin 2, 3
V & H sync input from
7801 pin 33 , 34
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