Haier HT-3768, Руководство по обслуживанию

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Table 4
Grounding Resistance
(R)
No. Function
Working
Voltage (V)
Positive
( )
Negative
( )
1 +16V POWER SUPPLY 16 0.43 1.8
2 AMPLIFIED AUDIO SIGNAL
OUTPUT
7.5 0.58 1.6
3
GROUND 0 0 0
4 RIPPLE FILTER 5.1 0.66 1
5 GROUND 0 0 0
6 AUDIO SIGNAL INPUT 1.7 0.76 2
7 NEGATIVE FEEDBACK 2.05 0.78 1.9
3. Analysis of vertical sync and vertical scan output circuits
The field sync signals segregated from compound sync signals are used to
activate the vertical frequency segregation system which commences when a set
amount of vertical sync pulse signals are tested. Of the sync pulse frequencies
obtained from segregation, some are transmitted to the vertical tooth wave
generator. The vertical frequency tooth wave, after geometric processing, is
transmitted from (16) of N204 (TMP8803SN) to (5) of vertical scan output IC
N402 (LA7840). The external resistor R443 (5.6K
Ω
) of N204 (16) provides a
reference current to the vertical tooth wave generator. The external capacitor
C244 (0.1uF) of pin (2) forms the vertical ramp wave. The vertical ramp wave is
sending the pin (4) of the vertical scan output integrated circuit N402 that is a
complete bridge current drive output circuit. After shaped and amplified the
vertical ramp wave is output from pin (2) of N402.
Information introducing functions and testing data for LA7840 maintenance is
listed in Table 4. if a cylindrical color card is installed then a fluke III digital
multimeter is used.
Table 5
Grounding Resistance (R)
No. Function
Working
Voltage
(V)
Positive
( )
Negative
( )
1 GROUND 0 0 0
2 VERTICAL SCAN WAVE OUTPUT 13 0.45 1.9
3 PUMP UP OUT
25 0.5
4 VERTICAL RAMP WAVE INPUT 0.95 0.9 1.25
5 WAVE CORRECTION 0.75 0.68 1.75
6 +25V POWER SUPPLY 25 0.5 2.95
7 VERTICAL SYNC DETECT 0.83 0.65 1.3
4. Analysis of horizontal sync and horizontal scan output circuits
As the horizontal oscillation circuit is installed inside N204 (TMP8803SN), . Some
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