Barco R762120 User manual

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
1
SERVICE SHEET
WARNING
THIS CIRCUIT BOARD IS HOT TO AC. THIS POWER SUPPLY, LIKE THE HIGH VOLTAGE POWER
SUPPLY, DOES NOT USE A LINE ISOLATION TRANSFORMER, MEANING A PORTION OF THE
CIRCUITRYISHOT-TO-LINEANDSHOULDBETREATEDWITHCAUTION.
Rev. 01
+CONV
SCAN FAIL
-17V
+30V
+17V
+230V
HTHD
-17V
+9V
-170V
R762120S
Voltage diagnostic
+CONV' Overvoltage

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
7
Block diagram
+300V
F176
IC179
SUPPLY
P3
6
5
4
C117
3
2
-
+
1
SUPPLY
GND
EX.
BLOCKING
I-SIMUL
CONTROL
ZERO
CROSSING
REF.
Primary
Secondary
Q101
P7
P1
P6
+Focus
+Conv
-Conv
393
1
+15V
F190
F191
F192
+Conv’
1
2
6
5
4
+30V
Q203
+Conv’
+30V
HTHD
-
+
393
1
-
+
393
7
+30V
Z197
5V6
Vref
Q208
Q227
+Conv’
+30V
On Horizontal Deflection
module
Lhigh freq
Hlowfreq
+30V
+17M
IC217
762120_A.drw
level detector
Overvoltage protection

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
8
Block diagram
762120_B.drw
4XDGUXSOHU
(+7WRVSOLWWHU
)RFXVYROWDJH5
)RFXVYROWDJH*
)RFXVYROWDJH%
)RFXVXQLW
*YROWDJH5
*YROWDJH*
*YROWDJH%
-
+
084 1
*YROWDJHVWDELOL]HU
3
-
+
084 1
9UHI
9
9
)URP(+7
PRGXOH
-
+
084 1
-
+
084 7
6)
9
9
+7+'
9
9 9
6)
+7+'
&219
9
&219
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9ROWDJHGLDJQRVWLF
Monitoring of the +230V and the -170V
Q203
+Conv’ +30V
HTHD
-
+
393
1
-
+
393
7
+30V
Z197
5V6
Vref
Q208
Q227
+Conv’
+30V
On Horizontal Deflection
module
Lhigh freq
H low freq
+30V
level detector
Overvoltage protection
toSFline
(J1-8)
G2
Killer

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
9
Technical description
Technical description G2 + DIAGNOSTIC (76 2120).
Introduction This board comprises :
- the SMPS for the convergence end stages and the Focus power stages.
- the stabilisation and alignment circuits of the G2 voltages.
- monitoring circuits of the +210V / -170V to cause scan fail if absent.
- the LEDs for diagnosis of the supply voltages and scan fail.
A. SMPS for +/- CONV and +FOC voltages.
This power supply uses the same TDA4601 as the main SMPS. We refer to the
description of this board for more details. We just limit here to the differences and the
control loop to generate the correct amplitude of these voltages.
Because of the high scanning range of the projector, from 15khz to 135khz, we apply
a tracking of the power supply with the line frequency. This means the power supply
forthepowerconvergencestagesincreaseswiththelinefrequency,but, not in a linear
way.
The available information on the line frequency is the +HTHD voltage. However, this
voltage is not linearly proportional for the full range of frequencies. Nevertheless, this
voltageisused for tracking, butanadaptationof the gaininthe feedback willbe needed
in the second range.
TheTDA4601(IC179) totallyrelieson the+15V(derivedfromthe +17M) deliveredbythe
first or main SMPS and the +300VM.
The transformer and associated rectifier circuits provide the +FOCUS, +/- CONV and
the +CONV for the feedback control loop discussed hereafter.
B. Control loop / Feedback / Adaptation.
To obtain a tracking with the line frequency, a portion of the +HTHD voltage is applied
to the base of Q208.
Themainloop isrealisedby applying the+CONVvoltage to thebaseof Q203,theerror-
amplifier.Theamplitude ofthefeedback dependson the statusofthe output ofthelevel
detector LM393 (IC216) , pin 1. If that pin 1 output is low (=ground), R200 is added in
parallel on R201. In the other case R200 is hooked up to the +30V (output of level
detector).
Pin 2 of the LM393 is set at 5.6 volt with Z197. REL2 is connected to the collector of
Q8 on the HOR DEFL board. For the second range, this line is low or ground level and
pin3is then lower than thezenervoltage.Pin 1 is then atgroundleveland consequently
R200 is put in parallel with R201. The feedback is changed to compensate for the
decreaseof the +HTHD voltage.
Via an insulating opto-coupler, the collector current of Q203 is transferred to pin 3 of
theregulatingTDA4601.
The +CONV voltageisalso applied to anotherleveldetectorin IC216, pin5.Thesame
referencevoltageof5.6voltsis applied to pin 6. When an overvoltage situation occurs,
Q227 saturates and the collector of Q203 drops to ground level. The SMPS switches
into a safe loop, whereas the output voltage is dropped to a minimum.

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
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Technical description
If,ontheotherhand, the HTHD voltage is too ,the+CONVvoltagedropsalso via D235/
R227.
C. Monitoring of the +210V and -170V.
A very stable Vref voltage is formed with IC2 (33V) and buffered with an OPAMP.
IC2stabilizesa33volts whichisthendividedbyR14/R1to exactly 10 volt and buffered
toprovide sufficient current.
If the +210V were absent, the Vref would disappear and the monitoring circuit cannot
work. The +9V takes over in this case and installs a reference voltage via Z1 / D11.
ThisVref of 10 volt is used for the level detectors monitoring the supply voltagesofthe
video power stages : the +210V and -170V.
Theabsenceofoneorbothofthesevoltagescandamage the picture tubes. The Scan
Failline switches low through Q1 as soon one ofthe voltages drops below some level.
D. G2 voltages. 1. Stabilisation.
The G2 voltages must be very stable to avoid thermal drift, and, they should be
adjustable between 400V and 1020 volt.
Thevoltagecoming from the unit 762120Sisalready very stable since itiscomingfrom
a stabilised source, the EHT.
The series output resistor in the unit forms together with P2, P3, P4 and R17 a divider.
If we can stabilize the voltage at the node mentioned Adjust for 1020V with P1 we
also have a stable G2 voltage at the sliders.
That 1020 volt point is sensed with the divider R15 / R13/ P1. Since the Vref is 10volt,
the output of the OPAMP will change until pin 13 is also at 10 volt.
Any voltage difference due to a change of the 1020 volt is adjusted by Q2 which will
feed a current from to the (negative) output of the OPAMP via the voltage dropping
Q2 transistor. Note that Q2 is needed because the 1020 volts is a too high voltage for
the OPAMP. A high voltage transistor such like the ON4046 (BU508A) is therefore
required.
2. G2 - Killer.
The G2 voltages must drop very quickly to zero in the event of a scan failure and at
switchingoffthe projector. There is ariskthatthe spot suppression does notsufficiently
work when these voltage are too high.
Thedropof theG2voltage is realisedwithD100-D104 taking theheavydrop ofthe+17V
and +30V at information to cause a heavy conduction of Q2.
In the event of a scan failure, Q110 gets forward biased as its emitter Q2 becomes
negative.
E.LEDs for diagnosis. The presence of the various voltages are all displayed with green LEDs. The variable
voltages like the +HTHD and +CONV drive a LED through a transistor to obtain a
constant light output of the LED.
The scan fail diode D16 is red and shows that there is a problem in the horizontal or
vertical deflection (see these boards for more explanations).
R762120 Rev. 18.06.96

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
11
The alignment is restricted to the adjustment of :
- alignment of the +1020V
- pre-alignment of the BLACK BALANCE
ADJUSTMENTPROCEDURE 'G2CONTROL+DIAGNOSTICMODULE'
Adjustment procedure
HIGH VOLTAGE WARNING
To avoid DANGER TO LIFE, do not attempt to service the chassis
until all precautions necessary for working on HIGH VOLTAGE
equipment have been observed.
Alignment
WARNING: The power must be OFF before removing any connector from
circuit board or unit. Failure to do so may result in severe damage to the
projection unit.
-Turntheprojectoroff.
- Put the module on the extension boards.
- Connect to the VIDEO input e.g. an electronic colour test video signal.
- Switch the projector in the VIDEO MODE. Select source 1.
Preparation
Black balanceadjustment
P4(R) P3(G) P2(B)
P1 Adj. 1020V
Measure point for the
+1020V adjustment (R15)

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
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- Connect to the resistor R15 (side wire soldering J3) a precision focus probe.
CAUTION: read carefully all safety instructions, mentioned in the user's
manual of the precision focus probe.
- Switch on the projector.
- Adjust the potentiometer P1 for +1020V read out.
Alignment +1020V
Black balance - Connect to the video input a colour bar signal.
- Proceed to Random access adjustment mode and highlight color balance.
Press ENTER to display menu R10 (refer to owner's manual of the projector)
Use the arrow keys to select black balance and then press ENTER.
Adjust the "cut off" for each color for a bar scale level of 50.
-AdjustCONTRAST to minimum(numberindicationbelow the barscaleof0) and
COLOUR until colour is off.
-Adjust BRIGHTNESS to mid-position (number indication below the bar scale of
50).
Proceed to the pre-adjustment of the black balance P2(B)-P3(G)-P4(R)
Observe the bars on the screen. If any trace of color appears on the black or
white bars then perform the following adjustments in low ambient light.
- Cover the blue and the red lens with the lenscap.
Short-circuit the two pins on the top
side of the respective colour driver,
see illustration.
AdjusttheGreenG-2 control P3 until
the green raster is just visible on the
screen.
Removeshort-circuit
-Coverthegreenandtheredlenswith
the lenscap.
Colour driver
Short-circuit the two pins on the top side of the respective colour driver, see
illustration.
Adjust the Blue G-2 control P2 until the blue raster is just visible on the screen.
Removeshort-circuit
- Cover the blue and the green lens with the lenscap.
Short-circuit the two pins on the top side of the respective colour driver, see
illustration.
Adjust the Red G-2 control P4 until the red raster is just visible on the screen.
Removeshort-circuit
Remove the lenscaps
The raster on the screen should appear white.
short-circuit
Adjustment procedure

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
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Note: if any coloration is still visible, then adjust the black balance ( Red cut-
off, and Blue cut-off) in theRandom access adjustment mode slightly to
eliminate any trace of colour.
Re-adjust brightness and contrast for optimum picture. There should be no
coloration between shades of gray.
Re-adjust color control at normal.
Adjustment procedure

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
14
Parts listing 76 2120
Parts listing R762120
SIT. ITEM NO. DESCRIPTION QUANTITY
20 R133036 SPR L 6 D 2,4D 6 CE 5
120 R133063 HTSN@A SOT93 I_MICA 28X 1
220 R133074 HTSN@A I_SIL W30
400 R3631049 SCR Z933 M 3 X 6 SS 1
30 R3631059 SCR Z933 M 3 X 8 SS 1
130 R3631059 SCR Z933 M 3 X 8 SS 3
230 R3631059 SCR Z933 M 3 X 8 SS 4
500 R3631239 SCR Z933 M 4 X 10 SS 2
401 R3661026 NUT D934 M 3 SS 1
140 R366988 NUT TRAD M 3 EDGE PLBK 2
240 R366988 NUT TRAD M 3 EDGE PLBK 2
402 R367502 SPR D6798AD 3,2D 6 STZN 1
10 R367699 RVT AVTRON2,5L 8,1 AL 6
1010 R367699 RVT AVTRON2,5L 8,1 AL 2
1000 R722276 LOCK49PCB UN CPL 1
100 R803607 HTSNG808 SMP2+G2 1
200 R804614 HTSNG808 SMP+G2 1
110 R804832 HTSN A GEN SPG 1XM3 LG 1
210 R804834 HTSN A GEN SPG 2XM3 LG 1
R762120A UNG1200 G2+CHK 1
R762120S UN G1200 G2+CHK SUB 1
Z3450110 WU CUSN 0,60 MM 40 1
C149 R111468 C EL RA 470M M 16E2 85 1
C100 R111477 C EL RA 100M M 25E2 85 1
C170 R111477 C EL RA 100M M 25E2 85 1
C101 R111486 C EL RA 47M M 50E2 85 1
C187 R111556 C EL RA 470M M100E3 85 1
C188 R111556 C EL RA 470M M100E3 85 1
C189 R111556 C EL RA 470M M100E3 85 1
C178 R111578 C EL RA 100M M400E4 105 1
C 12 R111718 C CE DI 1N K302E3 HV 1
C140 R112741 C CE MI 1N5K100E2 1
C 1 R112747 C CE MI 4N7K100E2 85 1
C226 R113720 C POMERA 47N K 63E2 85 1
C154 R113724 C POMERA 100N K 63E2 85 1
C216 R113724 C POMERA 100N K 63E2 85 1
C229 R113724 C POMERA 100N K 63E2 85 1
C 4 R113728 C POMERA 220N K 63E2 85 1
C148 R114090 C POMERA 1M K 63E2 85 1
C163 R1150051 C PPMERA 2N2J162E9 HV 1
C143 R115936 C PP RA 6N8J 63E2 85 1
D 16 R131662 D LED D3 T RD 1
D 9 R131667 D LED D3 T GN 1
D 10 R131667 D LED D3 T GN 1
D 13 R131667 D LED D3 T GN 1
D 14 R131667 D LED D3 T GN 1
D 15 R131667 D LED D3 T GN 1
D 18 R131667 D LED D3 T GN 1
D 19 R131667 D LED D3 T GN 1
D 20 R131667 D LED D3 T GN 1
D246 R131667 D LED D3 T GN 1
D253 R131667 D LED D3 T GN 1
D184 R1319025 D R BY255 1323A0 DO201 1
D185 R1319025 D R BY255 1323A0 DO201 1
D280 R131907 D R BY584 182085 SOD61A 1
D281 R131907 D R BY584 182085 SOD61A 1
D282 R131907 D R BY584 182085 SOD61A 1
D181 R131927 D R BY229 60007A TO220C 1
D182 R131927 D R BY229 60007A TO220C 1
D183 R131927 D R BY229 60007A TO220C 1
F176 R314143 F 5X20 F 2A H UL 1
F190 R314188 F TR5 T 4A L UL 1
F191 R314188 F TR5 T 4A L UL 1
F192 R314188 F TR5 T 4A L UL 1
F176 R314516 F A H+C 6A 5X20 BV B 1
I207 R131691 U 601-3 SFH DIP6 P 1
I179 R132787 U 4601-5 TDA SIP9 P 1
I217 R134010 U 7815 TO220 P 1
I 1 R134113 U 084 TL DIP14 P 1
I145 R134114 U 393 LM DIP8 P 1
I216 R134114 U 393 LM DIP8 P 1
J 1 R313525 J EUR2C MBS P64 E1C2S 1,6 1
J 2 R313525 J EUR2C MBS P64 E1C2S 1,6 1
L144 R302108 CORE TUBE 3,5 /1,3 X 3 1
L193 R305913 CH MNS AX NS 12 UH 3A 1
L194 R305913 CH MNS AX NS 12 UH 3A 1
L195 R305913 CH MNS AX NS 12 UH 3A 1
L168 R3061322 CH AX NS 10 UH 1
L144 Z3450110 WU CUSN 0,60 MM 40 1
P 1 R106733 R TCE H100K K 0W5 S10TS 1
P 2 R1076136 R THV V 5M M 0W5 1000 1
P 3 R1076136 R THV V 5M M 0W5 1000 1
P 4 R1076136 R THV V 5M M 0W5 1000 1
Q203 R1314072 Q BC547A N SS TO92 1
Q100 R1314131 Q BC557B P SS TO92 1
Q 2 R1325096 Q BU508A N P SOT93 1
Q141 V132599 Q BU2525A N P SOT93 1
R 16 R101358 R MF H 68K J 2W E7 1
R211 R101359 R MF H 82K J 2W E7 1
R 28 R101462 R MF H150K J 2W E7 1
R 29 R101462 R MF H150K J 2W E7 1
R 37 R101462 R MF H150K J 2W E7 1
R 38 R101462 R MF H150K J 2W E7 1
R169 R102498 R MF H E47J 0W6 1
R167 R103226 R MO H150E J 2W E10 1
R184 R103248 R MO H 10K J 2W E10 1
R185 R103248 R MO H 10K J 2W E10 1
R186 R103248 R MO H 10K J 2W E10 1
R164 R103600 R WW H E1 K 4W 1
R 17 R104668 R HV H 3M9 J 0W5 3500 1
R250 R104668 R HV H 3M9 J 0W5 3500 1
R251 R104668 R HV H 3M9 J 0W5 3500 1
R 15 R104678 R HV H 10M J 0W5 3500 1
R151 V1026006 R MF H 1K F 0W6 E4 1
R156 V1026006 R MF H 1K F 0W6 E4 1
R 1 V1026008 R MF H100K F 0W6 E4 1
R174 V1026424 R MF H 27E4 F 0W6 E4 1
R103 V1026655 R MF H475E F 0W6 E4 1
R 13 V1026727 R MF H 56K2 F 0W6 E4 1
T180 R774323 T G1200 SMP VAR 1
Z200 A509022 D TVS 33V 1500WU CB429 1
SIT. ITEM NO. DESCRIPTION QUANTITY

Date: 10/02/98 R762120
G2+DIAGNOSTIC R762120
15
Spare parts 76 2120
R313525
R804832
R774323
R804834
R314143
R314516
R722276
R366988
Fuse F190
R3141188
Fuse F176
Fuse F191
R3141188
Fuse F192
R3141188
R804614
R803607