Service manual

CA-13
Video Processing
RGB output, this circuit helps to prevent blooming. Excessive current draw in the picture tube will lower
voltage and hence decrease beam acceleration. This results in an increase of the sweep. Without ABL, the
blooming effect is usually seen when very bright images appear on the screen. ABL should prevent this and
extend the life of the picture tube.
<<Figure CA-11>>
Before sending processed RGB (red, green, & blue) outputs to the picture tube, ICX2200 integrates any
OSD (on-screen display), CC (closed caption), and PiP (picture in picture) into the video. At a particular
point in the televisions scan across the picture tube, where the video is to display an OSD object, a fast-
blanking (FB) pulse is sent from the microprocessor to the video processor at pin 14. This pulse of course
blanks the main screen video so that OSD can have precedence. Simultaneously, processed RGB from the
microprocessor enters the Jungle chip at pins 15, 16, & 17. This video fills in the blanked portion to be put
onto the main screen.
Picture-in-Picture
A few notes concerning PiP are noteworthy here. First those sets that have PiP will not be able to produce
video without the PiP module installed unless the PiP section is jumpered out. J2201M, J2202M, W2203,
and W2204 accomplish this. PiP signal enters the PiP module at pin 10 of connector PIPA1. This signal is
converted into RGB by the PiP processor and sent on to RGB OSD inputs of ICX2200. Pins 2 and 3 of
R2252M
C2235M
C2232M
R2253M
PROV
L2202
C2236M
R2254M
C2233M
PROV
+9VSW
L1207
+9VF
C1220M C1222
TP1203
+9VF
R1223M
C1223M
C1224 R1224M
R1222M
CM
AFC
C2231
C2229M
L2201
R2245M
R2244M
C2232
C2253
PROV
R2251
C2228M
1
2
3
4
5
DL2200
R2246M+9VSW
R2248M
W2206
C2230
R2250M
R2249M
Q2206
R2247M
C2227
W2207
Q2208
R2261M
R2262M
+9VF
R2260M
R2243M
C2224
Q2211
PROV
+9VSW
R2270
W2200
C2225
R2242M
+9VF
C2223
C2222 C2221
R2239M
R2236M
D2205 D2202
Q2209
R2265M
C2241
R2263
R2264
+15VSW
R2237M
Q2204
+15VSW
R2241M
C2218
R2240M
R2234M
R2230M
C2219
D2203
R2232M
Q2205
R2238M
+15VSW
D2204
R2235
R2233
C2220
ABL
12 45
44
43
42
41
40
39
38
37
3621
13
14
15
16
17
18
19
20
CIN
AFT
YIN
DC
VSW-OUT
BLK/DET
VIN
ACL
TV-IN
ABL
VCXO
GND
FBLNK
ROSD
GOSD
BOSD
D-VCC
ROUT
GOUT
BOUT
ICX2200
VERTICAL
ABL
EXT-
VIDEO
COMPOSITE
VIDEO-OUT
TVIN &
AMP CKT
(Pin 47)
CHROMA-
COMB