Friday, December 04, 2015

How to enter to service mode AKAI LTA-32C902 - LTA-37C902 troubleshooting and adjustments


Contents of this article 
  • Service mode ( Factory adjustment mode )
  • white balance adjustment
  • Troubleshooting  


AKAI LTA-32C902 - LTA-37C902 

SERVICE MODE AND ADJUSTMENTS 

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.
NOTE:
1.if no especial demand, please do not enter into the 20 th P item(design mode);
2.when tuning the 16 th item ,the storage data will be cleaned off, therefore, if not necessary ,please do not adjust it, the items of index number 1,2,3,4,5,6 are not necessary to adjust.
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.
Factory debug item
1. Auto color revise
AutoColor
Firstly finish auto color revise first before factory debug. Revise in TV,YPBPR and PC respectively.
Requisite Meter
PC - one
HD signal source – one
DebugRevise in TV,YPBPR and PC respectively
Park the channel in C-3 under TV mode TV, then do AutoColor.
Input color stripe signal in YPBPR and do AutoColor.
Input window signal in PC, the window is white, black signal around.
The result will appear in screen after AutoColor adjustment,make the adjustment results of Rgain 
Ggain and Bgain close to 0 × 80,if the difference is too great,adjust the value of HWUC_CON(auxiliary saturation),and readjust the AutoColor.
White balance, color temperature adjustment
1. Requisite Meter
CHROMA 7120 color analyze instrument
or same function instrument,contain color coordinate – chroma diversion card one
White balance adjusting frock
request the video output range 0-1V is adjustable,750hm loadone
2. Prepare
A. connect all equipments, switch the condition of LCD TV to AV.
B. Set the picture of LCD TV for standard condition
C. Set the distance of light receiver of white balance from center place of LCD display screen for 15cm +/- 3cm .
D. Make sure that the environmental brightness is below 2cd/mP2P
3. White balance, color temperature adjustment
Before adjusting it, put the first LCD TV in AV condition, and the image in standard condition, white balance adjust frock send the white vertical signal output from video into AV, adjust output range of balance adjust frock, make the brightness of the LCD TV 200±20cd/mP2 P(use CHROMA 7120 color analyze instrument to obtain the brightness ),then fix the video output range of white balance adjust frock(until all the LCD TV are adjusted).
Enter into white balance adjusting item of factory mode, change R,G,B value(try best to adjust this 3 value biggest) .
Make color temperature coordinate value accord with that of the table below (error value within ±4%)

SYMPTOMS AND CORRECTION
Symptom One:Display card 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 DD ( 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 snowflake 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 can not be controlled.(inc red lamp is on but the TV is off, remote control and local keys can not control the TV ,etc.)
Reason and Resolve:the LCD TV can not work abruptly, power off and turning it on again.