SHARP LC-32G4U- LC-32G4D - LC-37G4U- LC-37G4UG4D SERVICE MODE POWER SUPPLY CIRCUIT AND BACK LIGHT INVERTER CIRCUIT

SHARP LC-32G4U- LC-32G4D - LC-37G4U- LC-37G4UG4D SERVICE MODE POWER SUPPLY CIRCUIT AND BACK LIGHT INVERTER CIRCUIT

SHARP LC-32G4U- LC-32G4D - LC-37G4U- LC-37G4D 

SERVICE MODE POWER SUPPLY CIRCUIT AND BACK LIGHT INVERTER CIRCUIT  

ADJUSTMENT PROCEDURES
The adjustment values are set to the optimum conditions at the factory before shipping. If a value should become improper or an adjustment is required due to part replacement, make an adjustment according to the following procedure. (On the display)
If the monitor microcomputer (IC2004), receiver IC (IC2206), or HDCP key ROM (IC2208) are replaced, please note that the display unit must be replaced.
Applicable unit : DKEYHC269VJ
Adjusting procedure
Entering the adjustment process mode > COM BIAS adjustment > White adjustment
Entering the adjustment process mode
(1) When the AVC system is not connected
# While the main power to the display is off, hold down the "CH(DOWN)" key and "VOL (+)" key on the upper part of the display and then turn the"MAIN POWER" "ON". The display will run in the "Display process mode".
(2) When the AVC system is connected
# While the main power of the display is off, hold down the "CH(DOWN)"key and "VOL (+)" key on the upper part of the display and then turn the "MAIN POWER" "ON". The display will run in the "Display process mode".
In each case of (1) and (2), "<K>" is displayed in the upper left portion of the screen. Then, pressing any key will bring you to the first page of the "Display Adjustment mode".

 To exit the adjustment process mode, turn OFF the main power.

Cursor UP - Moving up by one item or moving to the previous page (when at the top) Incrementing the adjustment value by one or executing the item (in the case of W or R items)

Cursor DOWN - Moving down by one item or moving to the next page.(when at the bottom) Decrementing the adjustment value by one or executing the item (in the case of W or R items)

Cursor RIGHT - Moving to the right by one item or moving to another page. (in the case of the initial page) Moving to the right by one item.

Cursor LEFT - Moving to the left by one item or moving to another page. (in the case of the initial page) Moving to the left by one item.

ENTER - Test pattern off Executing the item (in the case of W or R items)

INPUT - Moving to the next page Moving to the next page

CH (UP) - Moving up by one item or moving to the previous page (when at the top). Incrementing the adjustment value by one or executing the item (in the case of W or R items)

CH (DOWN) - Moving down by one item or moving to the next page (when at the bottom).Decrementing the adjustment value by one or executing the item (in the case of W or R items)

VOL (+) - Moving to the right by one item or moving to another page (in the case of the initial page).Moving to the right by one item.

VOL (–) - Moving to the left by one item or moving to another page.(in the case of the initial page).Moving to the left by one item.

Adjustment
COM BIAS adjustment
Shift to the "COM BIAS" item with the cursor UP/DOWN key and select a numeric value with the cursor RIGHT/LEFT key.
Changing the numeric value with the cursor UP/DOWN key will make appear the test pattern. Make an
adjustment so that the flicker near the center of the screen is minimized.
White balance adjustment
Connect the AVC system, start the unit, and then perform a white balance adjustment on the display. Changing the numeric value with the cursor UP/DOWN key will make appear the test pattern. Make an adjustment so that the flicker near the center of the screen is minimized.
# Procedure
# Bring up the adjustment display (High side: 200 gradations, Low side: 48 gradations).
# Adjust "R GAMMAL" "G GAMMAL" "B GAMMAL" so that the 48 gradation pattern becomes normal. Adjust the chromaticity of the Low pattern (on the right of the display) so that it is set to x = 0.276 and y = 0.283.
# Adjust "R GAMMAH" "G GAMMAH" "B GAMMAH" so that the 200 gradation pattern becomes normal. Adjust the chromaticity of the High pattern (on the left of the display) so that it is set to x = 0.295 and y = 0.305.

Lamp error detection
Feature description
This liquid-crystal color TV incorporates a lamp error detection feature (lamp error detection) that automatically turns OFF the power for safety under abnormal lamp or lamp circuit conditions. If anything is wrong with the lamp or lamp circuit or the lamp error detection feature is activated for some reason, the following will result.
a. The power of TV main body is turned OFF about six seconds after it is turned ON. (The power LED on the front of the TV turns red from green and keeps blinking in red (ON for 250ms and OFF for 1sec).)
b. If 1 occurs five times consecutively, it becomes impossible to turn ON the power. (The power LED keeps blinking in red (ON for 250ms and OFF for 1sec).)
Measures
Checking with lamp error detection OFF
While the "MAIN POWER" switch is off, hold down the "CH(DOWN)" and "VOL(+)" keys and then turn the "MAIN POWER" on. The display will run in the "Display process mode" ("<K>" will appear.). If there is a problem with a lamp or a lamp circuit, the lamp will go out. (The power LED is green.)
Then, you can check the operation to see if the lamp and lamp circuit are abnormal.
Resetting the lamp error count
After you have finished checking whether the lamp and lamp circuit are abnormal, reset the lamp error count. If a lamp error is detected five consecutive times, the power cannot be turned on. Therefore, move to the "L ERR RESET" line, the fourth line on the first page of the "Display adjustment mode",using the Cursor UP/DOWN key. Then, reset the "L ERR RESET" value using the "Cursor LEFT/ RIGHT" key. In this case, press the "Cursor UP/DOWN" key to reset it to "0".

POWER SUPPLY CIRCUIT 

LC32/37G4D

LC-32G4U/G4D

BACK LIGHT INVERTER CIRCUIT 

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