②. No VOUT Output
Step 1: measurement HK-5 (TVS9) whether short circuit, or replacement
Step 2: measuring 75Ωresistance (RS117) impedence, or replacement
Step 3: monitor’s signal lines connected to the probe, directly from SGM9111
(US7) chip PIN 4 draw out the VOUT si g nal, o r repla ce me n t
Step 4: measuring 75Ω resistance (RS188), or re placement, and then monitor’s
signal lines connected to the probe, directly lead CVBS -VOUT signal
from 75Ω resistance (RS188) end, or KY2010 ruled out
③. Image Problem
Phenomenon 1 : there is no video signal, first excl u de HK-5 (TVS1-8) whether
short circuit, o r replacement; Measuring 75Ω(RV1-8) resistance, or
replacement, and then ruled out 100Ωresistance (RU1-8); Finally ruled out
TW2866 (can directly introduce video signal into TW2866 chip video input
end,PIN13/17/21/25, to rule out the chip is normal or not)
Phenomenon 2 : a fe w cha nnel image black screen, first r ul e out th e s of tw a re
settings, otherwi se introduce vi deo signal into TW2866 chip vide o input end,PI N
13/ 17/21/25, to rule out the chip is normal , or repla ce me nt
Phenomenon 3: all black and white images or flower screen, to rule out 27 M
(Y4/Y5), then rule out software, or change TW2866
④. Voice Problems
Phenomenon 1: preview no voice, first without software Settings, the n
measuring 100 resistance (RS46) and capacitance (CS18) impedance, or
replacement, finally ruled out TW2866 (US1) (can directly introduce audio
signal into TW2866 chip audio input PIN 6, to rule out t he chip is normal or no t)
Phenomenon 2: voice talkback AOUT no output, measuring 3.9 K resistance
(RS60) + 390Ωresistance (RP24) resistance, or replacement, finally ruled out
TW2866 (US1) (directly lead AOUT signal from the TW2866 chip PIN2, to
exclude the chip is normal or not)