Tuner Information; Miscellaneous Adjustments - GE 31GT750YX3 Technical Service Data

P P P P P a a a a a g g g g g e 1 e 1 e 1 e 1 SET 4702 SET 4702 SET 4702
e 1 SET 4702 SET 4702

TUNER INFORMATION

TUNER V V V V V OL TUNER TUNER TUNER TUNER OL OLT T T T T A A A A A GE CHAR OL OL GE CHART T T T T GE CHAR GE CHAR GE CHAR
Pin Pin Pin Pin Pin VHF Lo VHF Lo VHF Lo VHF Low Band VHF Lo w Band w Band w Band w Band VHF High Band VHF High Band VHF High Band VHF High Band VHF High Band UHF Band UHF Band UHF Band UHF Band UHF Band
(1) AGC 2.5V 2.5V 3.0V
(2) NC 1.3V 4.3V 5.7V
(3) +5V 5.2V 5.2V 5.2V
(4) CLOCK 5.1V 5.1V 5.1V
(5) SDA 5.1V 5.1V 5.1V
(6) +5V 5.2V 5.2V 5.2V
(7) +5V 5.2V 5.2V 5.2V
(8) +33V 34.5V 34.5V 34.5V
(9) IF 0V 0V 0V
NOTE: VHF Low Band voltages taken on channel 2.
VHF High Band voltages taken on channel 7.
UHF Band voltages taken on channel 14.
ERR ERR ERR ERR ERROR CODES CHAR OR CODES CHAR OR CODES CHAR OR CODES CHAR OR CODES CHART T T T T
Err Err Error Code or Code or Code or Code
Err Err or Code
DEC DEC DEC DEC DEC HEX HEX HEX HEX HEX Err Err Err Error Location Err or Location or Location or Location or Location Condition Indicated Condition Indicated Condition Indicated Condition Indicated Condition Indicated
0 00 No error code -
1 01 16.0V fault 16.0V STBY source is failing.
3 03 12.0V run fault 12.0V source is failing.
4 04 T4 Chip Run supply failed.
8 08 T4 Chip X-ray protection caused high voltage shutdown.
9 09 T4 Chip (POR) Power supply problem at (POR) power on reset.
10 0A F2 PIP module error (POR) Power supply problem at (POR) power on reset/PIP.
11 0B Stereo decoder (POR) Power supply problem at reset/Stereo decoder.
16 10 Run IIC Bus held low Run IIC clock or data held low.
18 12 Standby IIC Bus held low Standby IIC clock or data held low.
23 17 Gemstar 4 Board Guide fatal error on set using Gemstar 4 Board.
24 18 Gemstar 4 Board Task monitor error on set using Gemstar 4 Board.
25 19 Gemstar 4 Board Watchdog error on set using Gemstar 4 Board.
26 1A Gemstar 4 Board Task monitor error on set using Gemstar 4 Board.
32 20 Gemstar 4 Board CPU error on set using Gemstar 4 Board.
34 22 Gemstar 4 Board Gemstar 4 fails to acknowledge.
44 2C F2 PIP module error F2PIP fails to acknowledge.
102 66 Octal DAC Octal DAC fails to acknowledge.
128 80 Stereo decoder Stereo decoder fails to acknowledge.
160 A0 Main or PIP tuner EEPROM Main or PIP tuner EEPROM fails to acknowledge.
186 BA T4 Chip T4 Chip fails to acknowledge.
196 C4 Main tuner PLL/DAC Main tuner PLL IC fails to acknowledge.
198 C6 Main tuner PLL/DAC Main tuner DAC IC fails to acknowledge.
ERR ERR ERR ERR ERROR CODES OR CODES OR CODES OR CODES OR CODES
If certain failures occur, the matching error codes will be stored in the EEPROM. These error codes will be displayed in parameters 1, 2, and 3. The
first failure error code will be stored at parameter 1 and the second failure error code will be stored at parameter 2. Parameter 3 will be updated to
display the most recent failure occurred in the chassis. If a failure of a bus IC occurred, the normal acknowledgment checking of that bus will be
disabled in the service mode and the address of that IC which failed will be stored in one of the error code parameters. After every repair is done to
the chassis it is recommended to check the error code parameters and reset them back to value 0.
TUNER TERMINAL GUIDE TUNER TUNER TUNER TUNER TERMINAL GUIDE TERMINAL GUIDE TERMINAL GUIDE TERMINAL GUIDE
τ
(1)
(2)
τ
(3)
(4)
τ
(5)
(6)
τ
(7)
(8)
τ
(9)

MISCELLANEOUS ADJUSTMENTS

NOTE: All procedures require an antenna connected and power applied
to the set.
HIGH V V V V V OL HIGH HIGH OL OLT T T T T A A A A A GE CHECK OL GE CHECK GE CHECK
HIGH HIGH OL GE CHECK GE CHECK
Tune in a picture. Set brightness, contrast, and color to minimum.
Connect a high voltage probe to the CRT anode. High voltage should
measure 30.5kV to 32.5kV.
SERVICE MENU SER SER SER SER VICE MENU VICE MENU VICE MENU VICE MENU
The following adjustment procedures are accessed thru a service menu. To access the service menu, turn the receiver on, press the menu button and
hold it down while pressing the power button. While holding down the menu button, release the power button and press the volume + button. The
screen will display a one line menu, on the left the parameter P0, and on the right the value of that parameter V0. Release buttons. Adjustments are
made by selecting the proper parameter and changing the value of that parameter. To change the parameter number use channel up and down buttons.
To adjust the current value of that parameter use volume + and - buttons. To access and change any of the adjustments, the proper parameter pass
number must be entered. This information is listed at the beginning of the alignment. When these parameters are modified, the T-Chip and the
corresponding EEPROM are updated. All service adjustments are bus controlled, except focus and screen.
NOTE: In order to adjust the RF AGC, audio or video levels, tuner, PIP, or stereo circuits, the Chipper Check hardware and software must be used.
This can be purchased from Thomson Electronics. Before making any changes to any of the values, record the On Set values.
SER SERVICE ADJUSTMENT PARAMETERS SER SER SER VICE ADJUSTMENT PARAMETERS VICE ADJUSTMENT PARAMETERS VICE ADJUSTMENT PARAMETERS VICE ADJUSTMENT PARAMETERS
P P P P P arameter arameter arameter arameter On Set On Set On Set
arameter On Set On Set
No. No. No. No. No. P P P P P arameter Name arameter Name arameter Name arameter Name arameter Name V V V V V alue alue alue alue alue
0 Pass number for service adjustment Must set to 76
parameters.
1 Error Code 1 0
2 Error Code 2 0
3 Error Code 3 0
4 Horizontal Phase 7
5 EW DC (Width) 21
6 EW Amplitude 12
7 EW Tilt 6
8 Top Corner Pin Correction 5
9 Bottom Corner Pin Correction 5
10 Vertical DC 34
11 Vertical Size 83
12 Vertical Countdown Mode 0
13 Red Bias 21
14 Green Bias 9
15 Blue Bias 5
16 Red Drive 40
17 Green Drive 37
18 Blue Drive 39
19 Gemstar Horizontal OSD Position 162
20 Gemstar Vertical OSD Position 68
21 Gemstar PIP Horizontal Position 40
22 Gemstar PIP Vertical Position 43
23 Gemstar PIP Window Vertical Size 3
COLOR COLOR COLOR COLOR TEMPERA COLOR TEMPERA TEMPERA TEMPERA TEMPERATURE TURE TURE TURE TURE
NOTE: See Service Adjustment Parameters to change drive and bias
values.
Press menu button for collapsed raster service line. Disconnect the
antenna. Preset the red, green, and blue drive values to 32. Adjust screen
control for a service line that is just visible. Adjust red, green, and blue
drives to obtain a white raster. Check the low light to high light gray scale
tracking. Repeat the procedure, if necessary, to obtain the best perfor-
mance
V V V V V alue alue alue alue
alue
Rang Range e e e e Rang Rang Rang Comment Comment Comment Comment Comment
- May not advance until value is set to 76.
0 - 255 Displays the first error detected. Set to 0 before exiting.
See Error Codes Chart.
0 - 255 Displays the second error detected. Set to 0 before exiting.
See Error Codes Chart.
0 - 255 Displays the last error detected. Set to 0 before exiting.
See Error Codes Chart.
0 - 15 Tune in a crosshatch pattern, adjust to center the pattern on
the screen.
0 - 31 Tune in a crosshatch pattern, adjust for slight horizontal overscan.
0 - 15 Set value to 12.
0 - 15 Set value to 6.
0 - 7 Set value to 5.
0 - 7 Set value to 5.
0 - 63 Tune in a crosshatch pattern, adjust to center vertically.
0 - 127 Tune in a crosshatch pattern, adjust for slight vertical over scan.
0 - 3 Set value to 0. ( 0 = Standard, 1 = Non-Standard, 2 = 50Hz,
3 = 48Hz )
0 - 127 Press menu button on the TV set for setup line.
0 - 127 Press menu button on the TV set for setup line.
0 - 127 Press menu button on the TV set for setup line.
0 - 63 -
0 - 63 -
0 - 63 -
0 - 255 Set value to 162.
0 - 255 Set value to 68.
0 - 255 Set value to 40.
0 - 255 Set value to 43.
0 - 13 Set value to 3.