Service manual

CB-25
Deflection Control
Both positive and negative vertical ramp signals are required for operation. IC2200 supplies these to pins 4
and 5 of the amp as non-inverting and inverting input. Pin 3 is an input for output stage VCC. Pin 7 is the
pump-up output. Vertical output comes from pin 2 of the amp to pin 4 of the yoke connector. The other
end of the yoke provides feedback to pin 5 of the vertical amp and to the horizontal pincushion correction
circuit.
<<Figure CB-24>>
The pump-up output from pin 7 feeds the CRT-protection circuitry. This circuitry provides a DC level to
pin 13 of IC6000, the microprocessor. The DC level at that pin should be between 3.6 and 5.1 volts. If
the voltage deviates from this range, the microprocessor will shutdown the set in 3 seconds. IC6000 will
have to be reset before the receiver can be turned on again. The purpose of this circuit is to prevent phos-
phor burn or worse, the severing of the neck of the CRT. Pump-up current is rectified and smoothed by
D2102 and C2108. R2109M and R2112M divide the resulting voltage before it passes through R2113M
to the micro. D2103 is a clamping diode.
D2102R2108M R2109M
C2108
D2103
R2112M
R2113M
+5VSBF
To Pin 13,
IC6000
From Pin
7, ICX2100
<<Figure CB-25>>
1
36
5
4
2
7
ICX2100
C2106
R2101M
+14VSW
-14VSW
C2103
CX2101
CX2102
D2101
R2102M
R2103M
CX2100 C2104
RX2105
CX2105
RX2106 RX2107
C2107
R2104M
RX2110
RX2111
RX2114
PROV
Vert-Output
Vert-Parabola
VDN, Pin
14, IC2200
VDP, Pin
13, IC2200
To CRT
Protection
Circuit
32" & 36"
ONLY