Sharp LC-26GA5F Service Manual page 48

LC-26GA5E
LC-26GA5E
LC-32GA5E
LC-32GA5E
Troubleshooting Table (continued)
Is the power supplied to the LCD CONTROLLER PWB? (P7707: +6/+4/+13V)
Check if the REG output -D3.3V_1/2 of IC7706/IC7704 (REG-IC) is sent properly.
Is the output signal of IC4601 (GAMMA) sent properly?
Adjustment process menu: Is the gradation pattern displayed
properly when setting "PATTERN1" in the second llayer of
"LCD CONT" to "02"?
Check IC4901 (QS-DRIVER) and its peripheral circuits.
Adjustment process menu: Is the gradation pattern displayed
properly when setting "PATTERN1" in the second layer of
"LCD CONT" to "02"?
Adjustment process menu: Is the gradation pattern displayed
properly when setting "PATTERN2" in the second layer of
"LCD CONT" to "1"?
Check IC4601 (GAMMA) and its peripheral circuits.
Is the input voltage at pin (62) (OS-TEMP) of IC2004
(microprocessor) 5V?
Is the harness connected correctly between the inverter GND
PWB and LCD CONTROLLER PWB?
The thermistor on the INVERTER GND PWB is faulty. Or
check the peripheral circuits.
Adjustment process menu: Is the gradation pattern displayed
properly when setting "PATTERN2" in the second layer of
"LCD CONT" to "1"? (Is it whitish or dark?)
Disconnect the FPC from SC4651 and SC4652. (To protect
the panel against damage)
Check the power supply voltage supplied to the panel (check
at SC4651 and SC4652).
No picture in the LCD section
YES
NO
YES
NO
YES
Data bit drop (gradation-related)
NO
YES
NO
YES
Noise is caused to the moving picture with the QS drive on.
NO
YES
NO
YES
The whole screen is whitish (LCD power supply).
YES
NO
YES
Check the FFC (LV, SC2201 - SC4601) between MAIN
PWB and LCD CONTROLLER PWB and input circuit of
IC4601.
Check IC4501 (LCD CONTROL) and its peripheral circuits.
Check the connection between SC4651 and SC4652 and
peripheral circuits of IC4501 (LCD CONTROL).
Check IC4902 (FIFO) and its peripheral circuits.
Check IC4901 (QS-DRIVER) and its peripheral circuits.
Connect the harness correctly or replace it.
Check the video signal circuits (IC4501, IC4901, IC4601).
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