Akai LTA26C902 LCD TV – How to enter service mode – adjustments

Service Mode (Factory Mode) - Akai LTA-26C902 - LTA-32C902 - LTA-37C902 - Audio amplifier schematic

Enter into factory menu
1. Enter into child lock of main menu in TV mode, press “OK, the password input box will appear.
2. Use remote control to input the follows in order: 7, red key, 9, blue key, then you can enter into factory mode menu. After entering into factory mode menu, sign of the factory menu M will appear.
Factory menu and setup
1. Factory menu display is below:
M
Index:
1HWUC_BRI 0x1F
The M denotes entering into factory mode now, the figures of index denotes the index number now, the HWUC_BRI denotes the name of adjusting item now, and the 0X1F denotes the numerical value.
2. Each adjusting item have only one index number, the operator press the numeric key or press P+/P directly.
Adjustment methods for factory menu
1.Select the adjusting item
You can skip to the adjusting items by pressing the number key, also can select the adjusting item in the order of P+/P-.when pressing the number key, if the adjusting item is 1~9,input the corresponding number keys and press down “OK”, if the adjusting items tens digit, input a tens digit. For example, press number key 8 when adjusting the volume, you can see the color which become green, then press down “OK”, the color of index number turns red, So you already selected corresponding volume adjusting item.
If adjust DVD preset, first input 1, then input 3,you can adjust DVD preset.
2. Adjustment methods
Adjust it according to the operating key in above list. For one act operation, press OK/V+. Example Auto Color, for some variable add/reduce, Example Volume, press V+/V- .
3. The illuminate of white balance and AutoColor adjustment method Index 11 is corresponding to manual balance ,press “OK” or “V+” to display three corresponding variable, press “P+/P-”to select, press “V+/V-” to adjust, press down menu key to exit.
The index of AutoColor is 12,press “OK”or “V+” to do color revision, then the adjusted value will display.
4. BBE plus adjustment
Index number of BBE plus adjustment is 22 and 23,adjust it by adjusting “V+/V-”,the value of W270F8E and W320F8E are set 0X09,but the W370F8E is set 0X0F.
5. Press down the DISPLAY first before switching the program number in factory mode, press P+/P- to switch before the display content do not disappear;
6. All menu functions are on in factory mode, if necessary you can use menu to check the items and effect test.
Audio amplifier circuit diagram

Troubleshooting (General)
Symptom One: Display cards of PC no image in DVI.

Reason and Resolve: If some display card of DVI can not receive the data when turning on the TV, there is no output; if pull out the DVI line abruptly, there is also no DVI output; Before starting PC, connect the DVI line with LCD TV steadily, So DVI can receive the correct date from DDC Display Data Channel） when turning on the TV,DDC is in chassis 24LC21.
Symptom Two： No picture but sound, on LOGO when turning on the TV, background light is bright.
Reason and Resolve: Check the connect line in up screen, and connect the line.
Symptom Three： No picture, no sound, no snow in TV mode, but AV is normal.
Reason and Resolve: Check the outside of high frequency (also bus and power supply), there is no problem, but no output from high frequency, so the tuner is disabled.
Symptom Four： LCD TV cannot be controlled.(inc red lamp is on but the TV is off, remote control and local keys cannot control the TV ,etc.)
Reason and Resolve: the LCD TV cannot work abruptly, power off and turning it on again.