Akira CT25N19AN – How to enter Service Mode – adjustments

How to enter the service mode and adjust parameters – Akira 25 inch CRT TV 

ALIGNMENT INSTRUCTION ( CHASSIS : 5N11) Akira CTV
1.EEPROM partial initializing
Go to the function set menu (there are two methods: a / b)
Press 'VOL+' key and 'VOL-' key on the control board at the same time and switch on power switch, then go to the function set menu.
After TV is on, press "factory" key (See Note 1) twin then go to the function set menu.
Press 'PM' key and 'SM' key on the control board at the same time until the “INITIAL PART OK” appears, this means the memory having been partially initialized. Operate repeatedly if the picture has no change.
** All of the TV set EEPROM must be partially initialized before ex-factory or after change of the Chroma IC NN5198 / NN5199 or fully EEPROM initialized after change of the EEPROM 24C04 (OR 24C08,24C16).
2. Do a search and store.

COMPLETE MACHINE GENERAL ADJUSTMENT

Screen Voltage Adjustment.
Press 'screen' key (See Note 1);
Adjust the screen knob of FBT to get a horizontal faintness beam line;
Press 'screen' key again or 'stand by' key to go to the normal work status.

Focus Voltage Adjustment.

Receive monoscope pattern. Set picture mode to standard status;
Adjust the focus knob of FBT to get the clearest sharp picture.

Horizontal centering adjustment
Receive monoscope pattern;
Press 'factory' key (See Note 1) one time and go to system parameter adjustment menu;
Press 'MENU' key, go to horizontal and vertical parameter adjustment menu;
Select 'H' POSITION by pressing 'PROG+' key and 'PROG-' key. Press 'VOL+' key and 'VOL-' key to adjust the horizontal center of the pattern at the center of CRT screen.
Exit system parameter adjustment menu by pressing 'factory' key twice.

PAL system vertical pincushion adjustment
Receive PAL system cross hatch pattern signal;
Press 'factory' key one time, go to system parameter adjustment menu;
Press 'MENU' key, go to horizontal and vertical parameter adjustment menu;
Select 'V LINE' and 'V SCURVE' by pressing 'PROG+' key and 'PROG-' key; press 'VOL+' key and 'VOL-' key and adjust corresponding parameter to obtain picture's vertical pin cushion a good status PAL system.

Vertical Size and Vertical Center Adjustment
Continue operation 3. Select 'V HEIGHT" and 'V POSITION', press 'VOL+' key and 'VOL-' key adjust corresponding parameter to obtain picture's vertical size
and vertical center adjustment a good status.
Exit system parameter adjustment menu by pressing 'factory' key twice.

White Balance adjustment
For Factory Auto Computer adjustment
a. Receive white balance test signal;
b. Set picture "MILD" mode.
c. Insert the special plug into CN002, press adjustment key which belongs to white balance adjustment equipment and go to auto white balance adjustment;
d. After adjustment well, remove the plug.
For Factory Auto Computer adjustment
a. Press 'factory' key one time and go to system parameter adjustment menu;
b. Press "MENU" key once, then go to the White Balance adjustment menu;
c. Press ‘Prog +' key and 'Prog -' key to select the R, G, B cutoff and R, B Driver.
d. Press 'VOL+' key and 'VOL-' key to change. Or using the below direct key
e. Key: 0 for SUB-BRIGHT, 1 for CUTOFF-R, 2 for CUTOFF-G,3 for CUTOFF-B, 4 for DRIVER-R, 5 for DRIVER-B
f. Recall for toggle the Sub-Bright adjustment (Min. contrast, some CPU version do not work)

Sub-bright adjustment

a. Receive PHILIPS signal;

b. Set picture "RICH" mode.

c. Press 'factory' key one time and go to system parameter adjustment menu;

d. Press digital key '0', select 'SUB-BRIGHT';

e. Press 'VOL+' key and 'VOL-' key until Grey scale signal can be seen;

f. Exit system parameter adjustment menu by pressing 'factory' key twice.

RF AGC adjustment

a. Receive 60dBuV monoscope pattern;

b. Press 'factory' key one time and go to system parameter adjustment menu;

c. Press 'PROG+' key and 'PROG-' key, select 'RF AGC';

d. Press 'VOL+' key and 'VOL-' key to change the value of 'RF AGC' until picture's noise disturbing just disappears ;

e. Exit system parameter adjustment menu by pressing 'factory' key twice.

NTSC system horizontal and vertical adjustment
Receive NTSC system cross hatch pattern. Adjust same as PAL system.

Warm up mode
a. Switch on power switch and Press 'factory' key one time; switch off power switch and switch on power switch again, at this time there is no signal white raster and TV
won't switch off automatically. TV receiver can be sent to warm up line.
b. Before exit warm up line, press 'factory' key three times continue, at this time exit warm up mode, there is no signal and the LOGO ‘AKIRA’ will appear.

NOTES:

1. Connect the remote IC PIN7 and PIN16 through a jiggle switch on the USER remote handset , this switch is defined as "screen" key; Connect the remote IC PIN8 and PIN16 through a jiggle switch on the USER remote handset , this switch is defined as "factory" key.

2. On the product line's alignment service we must use special memorizer that has been well written with respective correct version data.

3. If having no special memorizer that has been well written with data when servicing out of factory, we can use blank new EEPROM. Then the new EEPROM will be automatically totally initialized with default data after main power switch is on. Most parameters are free-alignment after initialized; only need adjust the several parameters of function set parameter and system parameter adjustment menu.

4. If no blank new EEPROM or no special memorizer that has been well written with data, we can use memorizer that has been written with old data instead, but must be totally reinitialized; the operation is as following:

a) After TV is on, press "factory" key twice, ¬then go to the function set menu;

b) Press 'AV/TV' key and 'P.M' key on the control board, the TV turns off automatically; this means the memory having been totally initialized. Operate repeatedly if the picture has no change;

c) Switch off and exit;

d) After initialized, adjust the several parameters of function set parameter and system parameter adjustment menu.

5. The parameters of function set parameter and system parameter adjustment menu mustn't be adjusted;

* Ensure no adjustment on the following parameter except those parameter mentioned here.

a) System parameter adjustment menu (This is coming from the NN5198/ NN5199)
AFT
VIF VCO
H VCO
VIFDET NEG
VIFDET INT
VIFDET EXT

b) The ninth digital and the tenth digital of function set parameter.
These parameters must be IC interior values. If the above parameters have been changed, we must partially initialize the EEPROM.

6. Two different initializing
a) Fully initialize: initialize the EEPROM's most work data and preset default value. Including: work parameter of NN5199, horizontal and vertical parameter, OPTION parameter (via. function set parameter), picture mode parameter, volume mode parameter and white balance parameter.
b) Partially initialize: only initialize work parameter of NN5199 and the ninth digital and the tenth digital of function set parameter (via. ISUD0, ISUD1,ISUD3,ISUD4,ISUD5),preset as interior values.

7. If use 25” or above Pure Flat tube, adjustment of horizontal size and pincushion distortion must be done as follows :
a) Receive 60dBuV PAL system monoscope pattern;
b) Press 'factory' key one time and go to system parameter adjustment menu;
c) Press 'MENU' key and select ' Position Menu ' as below
V POSITION for adjust vertical position > 00 to 07
H POSITION for adjust Horizontal position > 00 to 1F
V EHT for adjust vertical shape > 00 to 0F
H EHT for adjust Horizontal shape > 00 to 0F

d) Press 'MENU' key and select ' geometry Menu ' as below;
V-AMP for adjust vertical size > 00 to 7F
V_LINE for adjust vertical linearity > 00 to 3F
V_SC3 for adjust vertical S-correction X3 > 00 to 3F
H-AMP for adjust Horizontal size > 00 to 3F
EW-PARA for adjust Pincushion > 00 to 3F
EW-COR for adjust Pincushion corner > 00 to 0F
TRAPEZ for adjust trapezium > 00 to 3F
V_SC5 for adjust vertical S-correction X5 > 00 to 0F

e) Receive 60dBuV NTSC system monoscope pattern; Repeat the above step 7.2 to 7.4.
f) Exit system parameter adjustment menu by pressing 'factory' key twice.

8. Option Code
1. Press 'factory' key twice and go to Option Code Menu.

The first digit 8 Digit is set by Factory. The last two digit “9” and “A” is the random data from NN5198/NN5199

Click on the pictures to zoom in

COLOUR PURITY AND CONVERGENCE ADJUSTMENT
COLOUR PURITY ADJUSTMENT
BEFORE ANY ADJUSTMENTS DESCRIBED BELOW ARE ATTEMPTED,V-HIGH, B+ VOLTAGE AND FOCUSING ADJUSTMENT MUST BE COMPLETED.
1. Place the TV receiver facing NORTH or SOUTH.
2. Plug in TV receiver and turn it on .
3.Operate and warm-up the TV receiver at least over 30 minutes.
4. Fully degauss the TV receiver by using an external degaussing coil
5. Receive a crosshatch pattern and adjust the static convergence control roughly.
6. Loosen the clamp screw of the deflection yoke and pull the deflection yoke towards you.
7. Enter into ADJUST MENU .set the values of C-R,C-G,C-B to “00”.
8. Adjust the purity magnets so that green field is obtained at the center of the screen.
9. Slowly push the deflection yoke toward bell of CRT and set it where a uniform green field is obtained.
10. Tighten the clamp screw of the deflection yoke.

CONVERGENCE ADJUSTMENT

1. Receive a dotted pattern.

2. Unfix the convergence magnet clamped and align red with blue dots at the center of the screen by rotating (R,B) static convergence magnets.

3. Align Red/Blue with green dots at the center of the screen by rotating (RB-G) static convergence magnet.

4. Fix the convergence magnets by turning the clamped.

5. Remove the DY wedges and slightly tilt the deflection yoke horizontally and vertically to obtain the good overall convergence.

6. Fix the deflection yoke by wedges.

7. If purity error is found, follow “PURITY ADJUSTMENT” instructions.

FINAL INSPECTION AND ELECTRICAL FUNCTIONAL CHECK
CHECKING THE ELECTRICAL FUNCTION
1. Connect the power cord and connect the signal to RF input.
2. Check the power supply whether OK or not. Switch on the TV set and the LED is on.  Switch off the TV screen and should not have CRT spot within 3 sec.
3. Receive the channel 1 for monoscope pattern to check the picture focus and the round circle should not be distorted. The centre position, and VOS line/size are within spec.  Check the brightness, contrast and colour condition. Check the convergence, picture must be clear, focus OK and white balance are OK. Also check the complete screen picture quality. High voltage condition OK and the Screen picture must be OK.
4. Check all the functional keys must be working well.
5. Receive colour pattern signal and the system colour. (PAL/SECAM/NTSC). Check the power main on/off switch, brightness, volume, colour, contrast and tint. The
picture quality must not have colour noise, unbalance size and distorted condition.
6. Check the sound quality standards, Volume up/down are OK to spec, and sound output. Ensure the sound output is not distorted and noisy. No interference for DK/BG/I/M.
7. Use remote Control Unit for all types of function check and ensure OK.
8. Check the words display condition.
9. Shock test and make sure the picture and sound are not distorted and shifted.
10. Use strong and weak signal to check the colour picture condition. After adjust the signal level to 35-40 dB and the colour should not gone. The picture and sound must be OK. At 60 dB the picture should not have snow noise.
11. Ensure the factory mode setting are set. Set-off the factory mode function and last switch off the TV set.
12. All the “NG” sets must send for repairing and recording for reference.
13. Check the AV input and output the picture and sound must be OK