Wednesday, November 28, 2012

SHARP - 25RM100N _ SERVICE MODE AND ADJUSTMENTS DETAILS






For adjustments of this model, the bus data is converted to various analog signals by the D/A converter circuit.


Before putting unit into the service mode, check that customer adjustments are in the normal mode. Use the reset function in the video adjustment menu to ensure customer controls are in their proper (reset) position.



TO ENTER AND EXIT SERVICE MODE
  • While pressing the Vol-up and Ch-up buttons at the sametime, plug the AC cord into a wall socket.  Now the TV set is switched on and enters the service mode.
  • To exit the service mode, turn the television off by pressing the power button.
SERVICE NUMBER SELECTION
  • Once in the service mode, press the Ch-up or Ch down button on the remote controller or at the set.  The service adjustment number will vary in increments of one, from "S01" to "OP2.
DATA NUMBER SELECTION
  • Press the Vol-up or down button to adjust the data number.
  • Holding down both the Vol-up/CH-down buttons on the TV set at service mode for more than 2 seconds will automatically write the above initial values into IC2101.
There are still a few analog adjustments in this series such as focus and master screen voltage.  Follow the steps below whenever the service adjustment is required.

SCREEN ADJUSTMENT
  • Connect a oscilloscope between TP854 and GND on the CRT Unit.
  • Receive a good local channel.
  • Enter the service mode and select the service adjustment "S03" and set the data value to "00" to set the color level to minimum. (Record original data code under adjustment "S03" before changing) You may skip this step, if you selected a B/W picture or monoscope pattern.
  • Select the service adjustment "S19" and adjust the data value to "01", this turn off the luminance signal (Y-mute).
  • Select the service adjustment "S04" and adjust data value to obtain 2.35 volts on the oscilloscope screen.
  • Adjust the master screen control until the raster darkens to the point where raster is barely seen.
  • Adjust the service adjustments "S11" red, "S12" green and "S13" blue to obtain a good grey scale with normal whites at low brightness level.
  • Select the service adjustment "S19" and reset data to "00". Select the service adjustment "S03" and reset data to obtain normal color level.
  • Remove oscilloscope, and reset the master screen control to obtain normal brightness range.
SUB-BRIGHTNESS ADJUSTMENT

  • Receive a good local channel.
  • Make sure the customer brightness control is set to center position.
  • Enter the service mode and select the service adjustment "S04".
  • Adjust "S04" data value to obtain normal brightness level.
VERTICAL SIZE ADJUSTMENT
  • Receive a good local channel.
  • Enter the service mode and select the service adjustment "S09".
  • While observing the top and bottom of the screen, adjust "S09" data value to proper vertical size.
VERTICAL PHASE ADJUSTMENT
  • Enter the service mode and select the service adjustment "S06".
  • Adjust data value to "00".
  • Note: This must be set "00" when changed data retrace line will appear.
HORIZONTAL POSITION ADJUSTMENT
  • Receive a good local channel.
  • Enter the service mode and select the service adjustment "S07".
  • Adjust "S07" data value so that picture is centered.
CAPTION POSITION ADJUSTMENT [HORIZONTAL]
  • Receive a good local channel.
  • Enter the service mode and select the service adjustment "S18".
  • A black text box appears on the screen. (see Figure C below)
  • Adjust "S18" data value so that text box is positioned in the center of the screen.
3.58MHz TRAP ADJUSTMENT
  • Receive a good local channel.
  • Enter the service mode and select the service adjustment "S16".
  • This is a two position adjustment, "00" is ON, "01" is OFF.
  • For this Model should be adjusted as "00"
SHARPNESS AND AUDIO BALANCE ADJUSTMENT
Receive a good local channel.
Enter the service mode and select the service adjustments "S05" for sharpness and "S17" for balance.

SHARPNESS ADJUSTMENT
  • Adjust data value to "28"(center of data range) for sharpness adjustment.

AUDIO BALANCE ADJUSTMENT
  • Adjust data value to "20"(center of data range) for Audio balance adjustment.
ENERGY SAVE OFFSET ADJUSTMENT
  • Enter the service mode and select the service adjustment "S20".
  • Adjust data value to "23".
  • Note : This position is used to preset the level for the energy save function.
OTHER ADJUSTMENTS
  • Enter the service mode.
  • Adjust the following data values as listed below.
S21      "03"      DDE OFFSET
S22      "00"      OSD SETUP
S23      "00"      TUNER SETUP