Electrical AlignmentsEM5.1E8.EN 103
8. Electrical Alignments
Index of this chapter
1. General alignment conditions
2. Hardware alignments
3. Software alignments
4. Option settings
1502
B
8.1General Alignment Conditions
8.1.1 Start ConditionsWarning
All alignments
Perform all electrical adjustments under the following are on hot-part !
conditions:
5430
?Power supply voltage: 230 VAC/50 Hz (? 10 %).
C
?Connect the set to the mains via an isolation transformer SSBLOT
with low internal resistance.
Focus 1
?Allow the set to warm up for approximately 20 to 30 Focus 2
minutes.Screen
VG2
?Measure the voltages and waveforms in relation to chassis
ground (with the exception of the voltages on the primary 3642
TUNER
side of the power supply).
A
Caution: never use the cooling fins/plates as ground.
?Test probe: Ri > 10 M&, Ci < 20 pF.
CINCH SCARTV.SHIFT
?Use an isolated trimmer/screwdriver to perform the CL 26532041_060.eps
110402
alignments.
Figure 8-1 Top-view LSP
Perform all electrical adjustments with the following start
settings (for all CRTs):
?Set LIGHT SENSOR "off", by setting ACTIVE CONTROL 8.2.1 Vg2 Adjustment
to "off" with the remote control.
?Set CONTRAST to "75", BRIGHTNESS to "42" and In the frame-blanking period of the R, G, and B signals applied
COLOUR to "54" (via PICTURE menu).to the CRT, the "HOP" video processor inserts a measuring
?Set COLOUR ENHANCEMENT to "off" (via PICTURE pulse with different DC levels. Measure the black level pulse
menu).during the vertical flyback at the RGB cathodes of the CRT.
?Set DIGITAL OPTIONS to "Pixel Plus" (via PICTURE 1. Go, via the MENU key, to the normal user menu, select
menu), unless otherwise stated (for sets without "Pixel "PICTURE", and set "CONTRAST" and "BRIGHTNESS" to
Plus" (= Eagle), set to "Natural Motion")."0".
?Set DYNAMIC CONTRAST to "off" (via PICTURE menu).2. Activate the SAM.
?Set CATHODE DRIVE at "15" (via SAM - Alignments - 3. Connect the RF output of a pattern generator to the
General - Drive - Cathode).antenna input. Test pattern is a "black" picture (blank
screen on CRT without any OSD info).
8.1.2 Adjustment Sequence4. Set the channel of the oscilloscope to 20 V/div and the time
base to 20 us/div. Use external triggering on the vertical
pulse
Use the following adjustment sequence:
(caution: use a trigger point at the "cold" side!).
1. Set the correct TV-set "options" (after storing, restart the
5. Ground the scope at the CRT panel ("cold" side) and
set!).
connect a 10:1 probe to one of the cathodes of the picture
2. Rough adjustment of "Vg2" and "Focus".
tube socket (see diagram F).
3. Rough adjustment of "Geometry".
6. Measure the cut-off pulse during first full line after the
4. Allow the set to warm up.
frame blanking. You will see two pulses, one being the cut-
5. Accurate adjustment of "Vg2" and "Focus".
off pulse and the other being the white drive pulse. Choose
6. Accurate adjustment of "Geometry".
the one with the lowest value; this is the cut-off pulse.
7. Software alignments (cut-off, cathode drive, peak white,
7. Select the cathode with the highest V_dc value for the
white drive, etc).
alignment. Adjust the V_CUTOFF of this gun with the
SCREEN (lower) potentiometer on the LOT to the correct
8.2Hardware AlignmentsDC-value (tolerance is +/- 3 V_dc):
- 28 inch: 160 V.
- 29 inch: 160 V.
Note: The Service Alignment Mode (SAM) is described in
- 32 inch (LPD - Philips): 160 V.
chapter 5 of the Service Manual. Menu navigation is done with
the "CURSOR UP, DOWN, LEFT or RIGHT" keys of the remote - 32 inch (MEC - Panasonic): 170 V.
- 36 inch: 170 V.
control (RC) transmitter.
8. Restore "CONTRAST" to "75" and "BRIGHTNESS" to "42". |
ACEC
