Saturday, February 28, 2015

LG FLATRON 194WT SERVICE MODE AND POWER SUPPLY CIRCUIT

LG FLATRON 194WT

LCD MONITOR 


SERVICE MODE AND POWER SUPPLY CIRCUIT 

SERVICE MODE
1) Turn off the power switch at the right side of the display.
2) Wait for about 5 seconds and press MENU, POWER switch for 1 second interval.
3) The SVC OSD menu contains additional menus that the User OSD menu as described below.
a) CLEAR ETI : To initialize using time.
c) Auto Color : W/B balance and Automatically sets the gain and offset value.
(press key for over 3 sec)
d) AGING : Select Aging mode(on/off).
b) Module : To select applied module.
d) NVRAM INIT : EEPROM initialize.(24C16, press key for over 3 sec)
e) R/G/B-9300K : Allows you to set the R/G/B-9300K value manually.
f) R/G/B-6500K : Allows you to set the R/G/B-6500K value manually.
g) R/G/B-Offset : Allows you to set the R/G/B-Offset value manually.(Analog Only)
h) R/G/B-Gain : Allows you to set the R/G/B-Gain value manually.(Analog Only)
BLOCK DIAGRAM

1. EMI components.
This part contains of EMI components to comply with global marketing EMI standards like FCC,VCCI CISPR, the circuit included a line-filter, across line capacitor and of course the primary protection fuse.
2. Input rectifier and filter.
This part function is for transfer the input AC voltage to a DC voltage through a bridge rectifier and a bulk capacitor.
3. Energy Transfer.
This part function is for transfer the primary energy to secondary through a power transformer.
4. Output rectifier and filter.
This part function is to make a pulse width modulation control and to provide the driver signal to power switch, to adjust the duty cycle during different AC input and output loading condition to achieve the dc output stabilized, and also the over power protection is also monitor by this part.
5. Photo-Coupler isolation.
This part function is to feed back the DC output changing status through a photo transistor to primary controller to achieve the stabilized DC output voltage.
6. Signal collection.
This part function is to collect the any change from the DC output and feed back to the primary through photo transistor.
POWER SUPPLY CIRCUIT 
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