Tuesday, March 03, 2015

HOW TO ENTER TO SERVICE MODE AKAI 29CT42FSQ – 21CT06FS – 15CT22FS – 29CT06FS AND CIRCUIT DIAGRAM

CRT TV

AKAI 29CT42FSQ21CT06FS15CT22FS29CT06FS 

SERVICE MODE AND CIRCUIT DIAGRAM 

Adjustment method
Main power +B setting
Receive standard color pattern RF signal
set picture to “ Standard Mode” . Adjust VR501to get +B (VD631 -) voltage =110 V 7

 I2C bus control adjustment methed: enter and exit factory mode

1) For remote controller of factory continuous push [test] key on remote controller, the TV mode will change as follow:
Normal  > M  >BUS OPEN,  you can select “M” ( factory mode ) or “normal” mode.
2) For remote controller of user
Push [menu] key,
> display picture manual >push digital key 8500 > display M.
Push [standby] key , exit factory mode and TV will be standby
MENU8 Geometrical adjustment .
Receive standard Crosshatch pattern signal for PAL system .
1) Adjust VSLOPE value,to the horizontal line just appear from half bottom shadow.
2) Adjust VSHIFT value
,the center horizontal line correspond to CRT vertical center.
3) Adjust Vamp value
,to get 90% of vertical picture contents would be displayed on CRT.
4) Adjust HSHIFT value
, to get the picture horizontal center correspond to CRT horizontal center.
5) Receive standard Crosshatch pattern signal for NTSC system, and again adjust.
MENU7 AGC-TOP adjustment
Receive 60dBu (1mv)VH color bar signal
, adjust AGC valuevoltage from high to low to picture noise reduce gradually to be just disappeared.
MENU9 CRT cut-off and white balance and sub-brightness adjustment.
Reseive gray and white 2 steps signal.
a) CRT cut off adjustment.
1. push [
P+][ P-] key to select “SC”, push [ V+][ V-] key then automatically vertical scan will be stopped.
2. adjust SCREEN control on Flyback transformer to get the darkest single horizontal line (red
,green,Mor blue,sometimes shows more yellow more purple or more white).
3. push [V+][V-] key again, vertical scan work repeat.
b) white balance adjustment
1. select RD/BD menu.
2. adjustment RD/BD to get color temperature as x=281, y=311.
c) sub-brightness adjustment (use stair case signal)
1. select SB MENU.
2. adjust SB to get the darkest step being on or off.
CIRCUIT DIAGRAM 
CLICK ON THE IMAGE TO ZOOM IN