Philips L06.1E AA General Alignment Conditions, Hardware Alignments, Alignments L06.1E

8. Alignments

Index of this chapter:

8.1General Alignment Conditions

8.2Hardware Alignments

8.3Software Alignments

8.4Option Settings

8.1General Alignment Conditions

8.1.1Default Alignment Settings

Perform all electrical adjustments under the following conditions:

•Power supply voltage: 230 VAC / 50 Hz (± 10 %).

•Connect the set to the mains via an isolation transformer with low internal resistance.

•Allow the set to warm up for approximately 20 to 30 minutes.

•Measure voltages and waveforms in relation to chassis ground (with the exception of the voltages on the primary side of the power supply).

Caution: never use heatsinks as ground.

•Test probe: 100 : 1, Ri > 10 Mohm, Ci < 3.5 pF.

•Use an isolated trimmer/screwdriver to perform alignments.

Perform all electrical adjustments with the following default settings (for all CRTs):

•Choose "Soft" picture mode with the "Smart Picture" button on the remote control.

•Set "Dynamic Contrast" and "Active Control" to "off" (if either one of them is present).

•Set "Brightness" to aligned value unless otherwise specified.

•Set "Contrast value" to 99.

8.1.2Adjustment Sequence

Use the following adjustment sequence:

1.Set the correct TV-set OPTIONS as described in paragraph "Options". After storing, re-start the set.

2.Rough adjustment of VG2 and FOCUS (potentiometers in “midway” positions; N.B.: wrong positions may cause error messages because of H or V-protection mechanism).

3.RF-AGC alignment.

4.Rough adjustment of GEOMETRY.

5.Allow the set to warm up.

6.Precise adjustment of VG2 and FOCUS.

7.Precise adjustment of GEOMETRY.

8.PIP alignments (if present).

9.COLOUR alignments.

10.Other software alignments.

8.2Hardware Alignments

Notes:

•The Service Alignment Mode (SAM) is described in chapter 5 "Service Modes, Error Codes, and Fault Finding".

•Use the cursor-, menu-, and OK-buttons of the remote control (RC) transmitter for navigation.

Alignments L06.1E 8. EN 59

G_16350_054.eps 060406

Figure 8-1 Focus 1, 2, and Screen Vg2 adjustment

8.2.1Vg2 Adjustment

In the frame-blanking period of the R, G, and B signals applied to the CRT, the video processor inserts a measuring pulse with different DC levels. Measure the black level pulse during the vertical flyback at the RGB cathodes of the CRT (pin 8 = R, 6 = G, 11 = B).

1.Connect the RF output of a pattern generator to the antenna input. Input a "black" picture (blank screen on CRT without any OSD info) test pattern.

2.In the SAM mode, set the “Normal Red”, “Normal Green” and “Normal Blue” values to “0” for “White Tone”.

3.Disable the black current loop (via the AKB bit).

4.Use the MENU key to enter the "user" menu, select "Picture", and set "Brightness" and "Contrast" to “0”.

5.Set the oscilloscope to 20 V/div and the time base to 20 us/ div. Use external triggering on the vertical pulse. Caution: use a trigger point on the "cold" side!

6.Ground the scope on the CRT panel ("cold" side) and connect a 10:1 probe to one of the cathodes of the picture tube socket (see circuit diagram F).

7.Measure at cathodes on the picture tube socket the DC- level of the measuring pulse (1st full line after the frame blanking) with respect to earth; N.B.: R = pin 8, G = pin 6, B = pin 11 of CRT socket.

8.Select the pin with the highest level found and adjust

V_cutoff by means of the Vg2-potmeter (lowest-one) on the

Line Output Transformer (LOT) to 145 +/- 5 VDC (for all screen sizes).

9.Reset "Contrast" and "Brightness" to their original values.

max.

VCUTOFF [VDC]

0V Ref.

E_06532_011.eps 110204

Figure 8-2 Waveform Vg2 alignment