Схема телевизора Philips chassis GR2.4

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PHILIPS GR 2.4 Chassis
16:9 Module / Comb Filter / Controls PCB / Directions for use / Electrical Adjustments ...Cont'd / Eurotext Module / Microprocessing Listing / Nicam BGL IF (J)
Nicam BGL IF (K) / Nicam Module (J) / Nicam Module (K) / Power Supply / Safety Parts / Scan Velocity Modulation / Scanning Module / SOPS Module / Video Processing
Stereo IF Module (L) / Stereo IF Module (M) / Testpoint Overview / Text (F1) / Text (F2) / Third Scart / Tube Base / Tube Base 16:9 / Tuner IF Audio Amp / Waveforms / Wiring Diagram
Adjustments
Setting conditionsAll electrical settings should be made under thefollowing conditions:* supply voltage: 220 -240 V
10%;50 Hz
* warming-up time 10 minutes* the voltages and oscillograms have beenmeasured with regard to tuner earth.* measuring probe: Ri > 10 M
; Ci < 2.5 pF.
1. Settings on the carrier board
1.1 +1 48V/+95V supply voltageConnect a voltmeter over C2631. Using R3635,set the supply voltage to +148V
0.5V for 25"
and 28" units or to 95V
0.5V for 21" units.
1.2 FocusingThis is set using the focusing potentiometer (onthe top of the line output transformer).
1.3 Vg2 settingConnect a pattern generator and supply ablanking frame signal (black picture). Switch theunit to the service default mode (see section 9).Connect an oscilloscope to the emitters oftransistors 7304 and 7364 on the picture tubemodule. Set the oscilloscope to frame fre-quency. Measure the DC voltage level of themeasuring pulses (see Fig. 7.2). Using the Vg2potentiometer on the line output transformer, setthe measuring pulse with the lowest DC voltagelevel to: * +130V
5V for all sets.
1.4 Horizontal synchronizationConnect pin 5-IC7470 to pin 9-IC7470. Supplyan aerial signal and tune the set. Adjust inservice menu(see section 9), sync.freq.bymeans of the menu +/- button until the picture isstraight. Remove the interconnection.
1.5 Horizontal centringSet using potentiometer 3461.
1.6 Vertical centringSet using potentiometer 3516.
1.7 Picture heightSet using potentiometer 3504.
1.8 Picture widthSet using potentiometer 3525.
1.9 East/west correctionIs adjusted with potentiometer 3521
1.10 Chroma bandpass filtera. Setting for PAL/SECAM sets (TDA4657)Connect a signal generator (e.g. PM 5138) topin 20 of the euroconnector (EXT1) and set itsfrequency to 4.286 MHz/0.5 Vpp. Switch the unitto EXT1. Connect pin 18-IC7306 to +12V.Connect an oscilloscope to pin 9-IC7306.Set 5301 to maximum amplitude. Remove theinterconnection.b. Setting for PAL sets (TDA4510)Connect a signal generator (e.g. PM 5138) topin 20 of the euroconnector (EXT1) and set itsfrequency to 4.436 MHz/0.5Vpp. Connect theunit to EXT1. Connect an oscilloscope to pin 9-IC7305 (TDA4510).Set 5301 to maximum amplitude
1.11 Chroma auxiliary oscillatorConnect a pattern generator and supply a PALcolour bar pattern. Connect pin 11-107305(TDA4510) to earth. Set 2313 so that the colouron the screen has practically stopped. Removethe interconnection.
1.12 White balanceConnect a pattern generator and select a whitepicture. Switch on the service menu (see section9) and select "WHITE BALANCE".Set the value of "Green" to 50(G/AMP), and theValue of "Blue" to 45(B/AMP). Value of "Red" to57(R/AMP). In most cases no futher adjust-ments are required.
1.13 Peak white limiterSwitch on the service menu (see section 9) andselect "WHITE BALANCE".Set "WH/LIM" to the value:
- 35 for blackline units- 51 for non-blackline units- 63 for 21" 110 degree sets- 45 for 29" sets
1.14 Cut-off points of the picture tubeConnect a pattern generator and select a blackpicture. Switch on the service menu (see section9) and select "CUT OFF". Set the value of "Red"to 30, and fore "Green" to 30, and for "Blue" to30. In most cases no futher adjustments arerequired.
1.15 OptionsSwitch on the service menu and select"OPTIONS" or "OPTION 1".Switch the options "ON" and "OFF" according towhether the following options are present:- "THIRD SCART" on a set with third scart.- "TELETEXT" on a teletext set- "MULTI SYSTEM" for multisystem sets- "UHF ONLY" for a tuner which can only be
tuned to the UHF band
- "NICAM" for stereo sets which can also receive
NICAM sound.
2.1 RF-AGCIf the picture from a strong local transmitter isdistorted, adjust 3016 until the picture is notdistorted.
2.2a MF-AFCFor multi system sets (PAL-BG/SECAM-DK).Connect a pattern generator to pin 8 of connec-tor G29 (IF-module) and select a frequency of38,9 MHz. Connect a voltmeter to pin 11 ofconnector G29. Adjust with 5001 the DC voltageto 1.9 V.
2.2b MF-AFC For all other sets.Connect a pattern generator to pin 8 of connec-tor G29 (IF-module) and select a frequency of38,9 MHz. Connect a voltmeter to pin 11 ofconnector G29.Adjust with 5001 the DC voltage to 2.3 V.
2.3 Stereo matrixConnect a pattern generator and supply a PALBG signal with stereo sound. Select only theright-hand channel sound. Go into servicemode. Choose SND stereo and pull out the rightconnector (seen from the front side of the set).Put volume maximum with volume button. Alignwith menu-button so that the sound is just nothearable in the left loudspeaker. Leave now theservice mode by putting the set in standby.
Error messagesInternal microcomputer errors and externalerrors will be signalled by displaying the errornumber (by OSD) and by continuous blinkingthe LED (video related errors only).
The last five errors will be remembered in thenon volatile memory (if possible), this is calledthe error buffer. After a startup of the system (onby main switch or on from standby) only oneerror will be added to the buffer (first in, first outprocedure), only errors different from the lasterror in the buffer, will be added to this buffer.The error will be cleared when the "standby"command is given while the system is in servicemenu mode. An active error is displayedcontinuously in service default mode. The bufferis shown in the service menu mode (Servicemain menu).
Electrical Adjustments (16:9)
Service menuFig. 7.1 shows the options in the Service Menulayouts. In the 16/9 model the option "E SIX/NINE has been added in the "service menu.For a detailed description of the "service defaultmode' and the `service menu" please refer tochapter 9 in the chassis manual GR2.4 AA.
Default values in option "E SIX./NINE"The default values are displayed as a two figurenumber in the middle of the bar at the bottom ofthe picture. The default value can be changedfor the optimum picture dimensions of the setconcerned using the "+" and "-" keys.
(picture height)
(east-west correction 16/9)
SIXT./NINE"
(picture width)
(east-west correction 4/3)
FOUR/THREE"
For the default values of the options in the othermenus please refer to chassis manual GR2.4 AA.
Adjustments in 16:9 mode.Following the replacement of the EEPROM(IC7710) and/or microprocessor (IC7708)diagram A. It is necessary to recalibrate the 16/9adjustments. Use a test circle (antenna signal)or a convergence pattern (video generator).
The adjustments are now as follows:Place the set in service mode.Select "E SIX/NINE" mode.
1. Picture heightSelect A (height), adjust the picture with +/-menu key in such a manner that the upper andlower edges just touch the mask. Now centrethe picture using R3516.
2. Picture widthA Select C (wide), adjust the picture with the +/-
menu key so that the picture remains 7 cmfrom the mask on both the right and left side.
B Select D (parab four/three), using the +/-
menu key adjust so that the vertical lines arestraight.
C Repeat A if it is necessary!
3. East/west adjustment in 16/9 modeSelect B (parab six./nine), using the +/- menukey adjust so that the vertical lines are straight.
Now switch to "standby".
(See Fig. 7.1)
Description
Possible fault
C error PIP module
+5 on PIP module, IC7406
C error IC7305(NICAM sets)
IC7305, +5 on IF module
C error IC7204
+5/+8 on IF module, IC7305
C error IC7205
+5/+8 on IF module, IC7205
C error teletext module
IC7910/IC7920, +5 on TEXT module
C error IC7710
IC7708/IC7710, +5 on IC's
C error tuner
+5/+14 on tuner, T57003
C error IC7308
+14 on IC7308
C error IC7309
+14 on IC7309
C error IC7820
BUS + blinking LED
C bus blocked
Survey of error messages on the screen
Testpoint Overview
Directions for use
1. Service-Default-ModeThe GR2.4 is equipped with a service defaultmode. The service default mode is a fixeddefined condition in which the television can beset.
1.1 Mode definitionThe definition of the fixed mode in the servicedefault mode is as follows:- all sound and picture adjustments are set in
the middle position (except volume, which isset at low and zoom set at zero) in 4/3 mode.
- The set is tuned to 475.25 MHz- system:* PAL BG or PAL I for single system sets
(MULTI-SYSTEM "OFF")
* SECAM LIDK for multi-system sets (MULTI-
SYSTEM "ON")
* SECAM DK for sets for Eastern Europe
(MULTI-SYSTEM "ON").
* PAL BG for sets for Eastern Europe (MULTI-
SYSTEM "OFF").
1.2 Service-default-modeThe service default mode is switched on bybriefly short-circuiting the pins M33 and M34(SERVICE) behind the INSTALL key on thecarrier panel when switching the unit on with themains switch. In order to indicate that the unit isin the service default mode, an "SER" appearson the screen.The service default mode can only be switchedoff by switching the unit to standby. The set isswitched off and then on again using the mainsswitch or mains plug, the service default moderemains switched on. Searching for transmitterfrequencies begins following the simultaneouspressing of both `install" keys on the remotecontrol. When the service default mode isoperational the following functions are switchedoff: