Wednesday, August 29, 2012

TOSHIBA 28MW7DB 28MW7DG SERVICE MODE AND ADJUSTMENTS - Self Diagnostic Function [1 of 2]




[1of 2]

ENTERING SERVICE MODE


  • Press the 'Mute' button on the remote control. A  mute symbol will be appeared.
  • Press 'Mute' button again and Hod it.
  • While pressing the "Mute" button, press "Menu" button on the front panel of the TV.
  • Will display the adjustment Menu.
  • Press 'Mute' button on the TV. "S" will be displayed on the upper right corner of the screen.
KEY FUNCTION IN THE SERVICE MODE
  1. A single horizontal line ON/OFF >> [-/---] button on the remote control or 'Power' button on the front panel of the TV.
  2. Test signal selection >> 'Power' button on the remote control.
  3. Selection of the adjustment item >> Channe Up/Dn button, either on the remote control or at the TV.
  4. Change of the data value to selected item >> Vol (+/-) either on the remote control or at the front panel of the TV
  5. Adjustment menu On | Off >> Menu button.
  6. Initialization of memory >> Call + Channel [Up] button on the TV. (Never try to perform initialization unless you have been changed the memory IC) 
  7. Reset the count of operating protect circuit to "00" >> Call + Channel [Dn] button on the TV.
  8. R-CUT selection >> 1 button.
  9. G-CUT selection >> 2 button.
  10. B-CUT selection >> 3 button.
  11. CNTX selection >> 4 button.
  12. COLC selection  >> 5 button  ----- Color thickness correction.
  13. TNTC selection  >> 6 button ----  [Note: May display differently depending on the setting of the receiving color system.  COLP = PAL |  COLC = NTSC | COLS = SECAM]
  14. Test Audio Signal On/Off  >> 8 button.
  15. Self diagnostic display On/Off >> 9 button.
SELECTING THE ADJUSTING ITEMS
  • Every pressing  of the 'Channel Up' button in the service mode, changes the adjustment items.
ADJUSTING DATA
  • Press of 'Volume ( +/- )' button will change the value of the data in the range from [00H to FFH].  The variable range depends on the adjusting item.
TO EXIT SERVICE MODE
  • Press the "Power" button to turn OFF the TV once.
INITIALIZATION OF MEMORY DATA OF QA-02.
  1. Enter the 'Service Mode' and select any register item.
  2. Press and Hold the 'Call' button on the remote control, and press 'Channel Up' button on the TV.  The initialization of QA-02 is completed.
  3. Check the picture carefully.  If necessary, adjust any adjustment item.  
  4. Perform "Auto Search Memory" function to make sure it works correct.  
TEST SIGNAL SELECTION
  • Every pressing of 'Power' button on the remote control changes the built-in test patterns on the screen in 'Service Mode'.  [Toggle between NTSC signals (14 patterns) => PAL signal (14) patterns => signal Of =>]
SELF DIAGNOSTIC FUNCTION
  1. Press (9) button on the remote control during display of Adjustment Menu in the Service Mode.  The diagnosis will begin to check if interface among ICs are executed properly.
Diagnosis Screen
==================================

                    <SELF CHECK>

 2390****
POWER      : 00
BUS LINE  : OK
BUS CONT: OK
BLOCK      : UV  V1  V2  QV1
==================================
  • 2390**** is part number of microcomputer.
  • Operating number of the protecting circuit  --- '00' is normal.  When indication other than '00' over current apts to flow, and circuit part may possibly be damaged.
  • BUS LINE CHECK: 'OK' is normal.  [SDA 1-GND = SDA-GD short circuit.] [ SCL 1-GND = SCL-GND short circuit] [ SCL 1-SDA 1 = SCL-SDA short citcuit.]
  • BUST CONT ---'OK' is normal. (When indication shows "QoooNG", the device with the number may possibly be damaged.)
  • BLOCK: (UV=TV reception mode.  V1=Video 1 input mode.  V2=Video 2 input mode]
Others

Indicated color of mode now selected: Green and Red.
Indicated color of other items: White.

Green: Normal.
Red: The microcomputer operates to provide judgement of no video signal.  The red color is still indicated though the signal is input, failure may exists in input signal line including QV 1

QV 1 :  In the case of indication Green = Normal
             In the case of indication red  with input signal = Failure may exist in output line including  QV 1.

  • In the case that the 'Power' indicator is blinking with intervals of (0.5) seconds, means the protecting circuit is operating, and circuit component may possibly be damaged.  Check related components.
  • In the case that the 'Power' indicator is blinking with interval of (1) second, protection circuit does not operate, but a part of Bus Line does not operate normally.  Check bus Line.
will continue: