Akai LM-H30CJSA, Руководство по обслуживанию

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9. Electronic Circuit Description
9.1 Main Board Circuit
1) Power
Refer to sheet 7 of PWB-0663 circuit diagram.
AC 110V~220V is applied to the LCD-TV through socket P801 on PB01 ( Power
module: PWB-0656) . PB01 (Power module: PWB-0656) outputs DC+24V to Inverter
U901 via P802 #1~#5 . DC+24V is also applied to Main Board via P803 #4 and then
fed directly to I010 #10 (Audio Amp. LA4282).
PB01 (Power module) also pr5V to Main Board via P803 #10. It is
applied to I044 (Audio processor MSP3410) through L031 . +5V is also applied to
Panel through L095 , I027 ( MOSFET: MI9933) , L042 and connector P005 # 19.
Beside, +5V is regulated by I016 (switching regulator : LT1084) to provide
+3.3V and also regulated by I015 (switching regulator : LT1117-adj) to provide
+2.5V for all chips.
2) PC Signal
Refer to sheet 1 of PWB-0663 circuit diagram.
The analog R.G.B. video signals are supplied through the
PJ03 ( D-sub connector)
and these three input signals are approximately 0.7Vpp in amplitude. R031
、
R032 and
R033 give resistance of 75
Ω
respectively for impedance matching. These R.G.B.
video signals are AC coupled via 0.047U capacitors C021
、
C016 and C013 , and then
fed into the I001 (AD converter) at #54
、
#48
、
#49 and #43 respectively. Then , R.G.B.
video signals are converted to their digital forms in I001 . The outputs of digital data
including 8 bits red, 8 bits green, 8 bits blue signals are assigned at #70~77
、
#2~9and
#12~19 of I001 , and applied to port A of I019 (Scaler : TP6760) . H.sync & V.sync
are applied to I001 #30
、
#31 and the processed signal taken from #66
、
#64 are fed into
I019 (TP6760) #18
、
#19. CLK signal is taken from I001 (AD9883-140) #67 and
applied to I019 (TP6760) #156. The LCD-TV is designed to have the DDC/2B
functions. DDC communication between the LCD-TV and computer is via PJ03
(D-sub connector ) #12
、
#15 and I004 #5
、
#6. The EDID data have written into the
I004 (EEPROM) in the factory during production , so computer will read out the
EDID from the I004 (EEPROM).
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