Electrical AlignmentsEM5E8.EN 97
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). Caution: never use the cooling
A
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):
8.2.1 Vg2 Adjustment
Set LIGHT SENSOR ?off?, by setting ACTIVE CONTROL to
'off' with the remote control.
Set CONTRAST to '75', BRIGHTNESS and COLOUR to Method 1 (with oscilloscope)
?40? (via PICTURE menu).In the frame-blanking period of the R, G, and B signals applied
Set COLOUR ENHANCEMENT to ?off? (via PICTURE to the CRT, the 'HOP' video processor inserts a measuring
menu).pulse with different DC levels. Measure the black level pulse
Set DIGITAL OPTIONS to 'Pixel Plus' (via PICTURE during the vertical flyback at the RGB cathodes of the CRT.
menu), unless otherwise stated (for sets without 'Pixel Plus' 1. Go, via the 'MENU' key, to the normal user menu, select
(= Eagle), set to 'Natural Motion').'PICTURE', and set 'CONTRAST' and 'BRIGHTNESS' to
Set DYNAMIC CONTRAST to ?off? (via PICTURE menu).'0'.
Set CATHODE DRIVE at ?15? (via SAM - Alignments - 2. Activate the SAM.
General - Drive - Cathode).3. Connect the RF output of a pattern generator to the
antenna input. Test pattern is a 'black' picture (blank
8.1.2 Adjustment Sequencescreen on CRT without any OSD info).
4. Set the channel of the oscilloscope to 20 V/div and the time
base to 20 us/div. Use external triggering on the vertical
Use the following adjustment sequence:
pulse (caution: use a trigger point at the 'cold' side!).
1. Set the correct TV-set ?options? (after storing, re-start 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 VDC value for the
white drive, etc).
alignment. Adjust the VCUTOFF of this gun with the SCREEN
(lower) potentiometer on the LOT to the correct DC-value
8.2Hardware Alignments(tolerance is +/- 3 VDC):
- 28": 160 V.
- 29": 160 V.
Note: The Service Alignment Mode (SAM) is described in
- 32": 160 V.
chapter 5 of the Service Manual. Menu navigation is done with
the 'CURSOR UP, DOWN, LEFT or RIGHT' keys of the remote - 36": 170 V.
8. Restore 'CONTRAST' and 'BRIGHTNESS' to normal
control (RC) transmitter.
(CONTRAST = 75 and BRIGHTNESS = 40). |
ACEC
