Connect all the boards according to wiring diagram, then power on and observe the display.
Method for entering factory menu:
- Press “INPUT”, “2”, “5”, ”8” and “0” in turn to enter factory menu.
- Press “CH+” and “CH-” to select adjustment items and press “VOL+” and “VOL-” to adjust value items.
- Press “MENU” repeatedly to exit.
- When software upgrading please enter factory menu first, select ISP of OPTION.
- Set ISP to 1 and you can begin to upgrade.
- After upgrade finished, it needs to set ISP back to 0.
- If the picture can’t display when upgrading, it needs to solder JB1 on main board.
- Unsolder JB1 again after upgrading.
Initialization
- Enter factory menu, select “OPTION”, “EEPROM” and “HOTEL OPTION” sub-menu, adjustment of items to see table.
IF AFC adjustment
- Disconnect J1(B face), input 38.9MHz PAL signal of 80dB to the pole of J1 near L11, Adjust L5 to value 1.25V of TP2. Enter factory menu, adjust TDA4470 from BG to LL, input 33.9MHz SECAM signal of 80dB, adjust R71 to value 1.25V of TP2 then solder J1.
- Input 184.25MHz(PAL/BG) RF signal of 60dBuv to RF terminal, adjust R64 to value 4V of TP4 and there should be no obvious snowy picture. Increase the signal to 90dBuv and it should be display normally and no obvious noise.
White balance adjustment of HDMI
- Input VG-849 signal from HDMI: TIMING854(800* 600/60Hz) and eighth-level gray scale signal of PAT920. Use color analyzer CA210 to adjust white balance.
- Enter submenu of COLOR TEMP, Select 9300k of color temperature
- Fixed value of B OFF, adjust R OFF and G OFF, let the color coordinate of the second level be (285, 293) and the brightness be about 3nit-6nit. Fixed value of B GAIN, adjust R GAIN and G GAIN, let the color coordinate of the seventh level be (285, 293). Adjustment R OFF, GOFF, R GAIN and G GAIN repeatedly until the value of the two levels gray-scale are (285, 293).
- VGA/YPBPR/AV white balance check and correct
- Input VG-848 signal of VGA to VGA terminal: TIMING854(800*600/60Hz) (PATIERN:CROSS) and auto adjust to full screen, then input PAT948 Black/white signal, enter factory menu ADC ADJ, select AUTOTUNE and wait for OK display. Input PAT920(8 gray levels), check if the white balance is normal, if not, enter COLOR TEMP menu and set ALL COLOR to 0 and fine adjust according the above method.
- Connect VG-848 signal of YPBPR to YPBPR terminal and input TIMING972(1080i/60HZ) 100% color bar of PAT976(include black/white bars), Enter ADC ADJ submenu, select AUTOTUNE and wait for OK display. Input PAT920(8 gray levels), check if the white balance is normal, if not, set ALL COLOR to 0 and fine adjust according the method stated above.
- Input AV signal (PM5518, 8 gray levels, NTSC) to VIDEO1 terminal, check if the white balance is normal, if not, set ALL COLOR to 0 and fine adjust according the method of stated above.
Note: it can’t set back to 1 once ALL COLOR changes to
0.
Working principle analysis of the unit
The RF signal received by antenna will be sent to tuner
TUNER101, then IF signal will be obtained through high amplifier and mixed
frequency, through pre-intermediate amplified by V15, then it will be sent to
acoustic surface-wave Z17 to do IF filter and get better IF characteristics,
then it will be sent to N3 (TDA4470) to do intermediate amplification,
phase-locked loop VCO and synchronous wave detection to get video signal TV-V;
after pre-intermediate amplification IF will also be sent to acoustic
surface-wave Z16 to do filter at the same time, then it will be sent to TDA4470
to do intermediate amplification and output the second sound intermediate
frequency signal (TV-SIF). The TV-V signal output from TDA4470 together with
TV-SIF will be sent to main IC NS2(MST9E19B). Video signals of VGA and HDMI will be sent to
MST9E19B, too. Video signal of YPbPr and Video RGB of SCART1 via video switch
NB24(PI5V330) will be sent to MST9E19B. Video signal V (CVBS) of SCART1, YPbPr
L/R and SCART1 L/R will be sent to MST9E19B. The main IC NS2(MST9E19B) is a
high performance and fully integrated IC, which can realize HDMI processing,
video demodulating, video switch selection, A/D and D/A conversion,
interlace/de-interlace processing, modes conversion, OSD and low-voltage
differential output, etc. And it also has functions of audio selection,
processing and MCU. The video signal via MST9E19B processing, output 4 pairs
differential signal and 1 pair clock signal for LCD panel display. TV-V output
from TDA4470 via double video amplifying, it will be sent to SCART1 for
AV-OUT. Audio signal via MST9E19B
processing will be sent to sound amplifier NV4 (R2S15102NP) amplifying to
speaker. TV-SIF via MST9E19B demodulating and sound processing then output to
NV3(LM358D) amplifying, the signal will be sent to SCART1 as AV-OUT.
