Acer AC501 User manual

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WARNING............................................................................................................................2
1. ALGNMENT PROCEDURE.............................................................................................3
A. Conditions................................................................................................................................3
B. Functions Alignment................................................................................................................3
C. Preset Timing:..........................................................................................................................6
2. OPERATION THEOREM ...............................................................................................12
A. Power Supply (1)...................................................................................................................12
B. Deflection...............................................................................................................................12
C. Video......................................................................................................................................12
D. Digital Controllable...............................................................................................................12
E. Function Block Diagram........................................................................................................13
F. Power Supply..........................................................................................................................14
G. Under Voltage Protection.......................................................................................................15
H. Degaussing CKT....................................................................................................................15
I. Deflection................................................................................................................................16
J. Video AMP. Circuit.................................................................................................................18
J-2. Video AMPLIFIER..............................................................................................................18
K. Digit Control..........................................................................................................................20
3. CONTROL AND CONMECT LAYOUT ..........................................................................21
A.Main PCB ...............................................................................................................................21
B.CRT PCB................................................................................................................................22
4. TROUBLE SHOOTING..................................................................................................23
A.Power Supply Check ..............................................................................................................23
B.Monitor Check Flow Chart.....................................................................................................24
APPENDIX A: PARTS LISTS .....................…………………………………………………...27
APPENDIX B: DISPLAY UNIT ASSEMBLY…………………………………………………...82
PPENDIX C: P.C.B. ASSEMBLY………………………………………………………………..96
APPENDIX D: CRT& YOKE ASSEMBLY…………………………………………………….106

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WARNING
1) This product contains components which are critical for X-radiation safety. Read the Service manual carefully for
proper replacement . Maximum 2nd anode vol tage use high impedance meter, connect (-) to chassis, use a high
voltage lead from (+) to 2nd anode.
2) Critical Components are marked with the symbol of in the material list. For continued protection against X-radiation,
replace only with same type and rating components.
3) Critical Components are marked with the symbol of # i n the material list. For continued protection against Low
Radiation, replace only with same part number.

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1. ALGNMENT PROCEDURE
A. Conditions
A-1. Equipments
Signal generator: A chroma-2250 signal generator to be provided as standard signal source.
Color analyzer: A minolta CA-100 color analyzer to be provided as standard color analyzer.
A-2. Presetting
Preset all of the VRs on main board to it’s mechanical center, and set FBT’s G2 control VR to it’s
minimum position before to proceed al ignment.
CRT faces to east direction, connects monitor and generator, warm up 30 minut es at least before to
proceed alignment.
A-3. Magnetic Environment
Unless otherwise specified, all performance tests are performed in a controlled magnetic environment,
the magnitude of the horizontal magnetic fi eld component in any direction will be less than 1000
gamma, the magnitude of t he vertical magnetic field component is defined in table 1 of engineering
specification.
B. Functions Alignment
B-1. Power Adj ust
Select timing #7 (VESA 48K 1024x768)with crosshatch pattern, adjust both horizontal and vertical
size cont rols to get display size within 262x196±1mm.
Adjust VR901 to get a DC 13.0±0.1V to be obtained on plus of C510.
Double check and make sure test points are within speci fications as defined i n following
VC930 (+) = 7.5 ± 0.5 V DC
VC942 (+) = 7.5 ± 0.3 V DC
VC943 (-) = -12 ± 1 V DC
VC946 (+) = 60 ± 2 V DC
VC947 (+) = 73 ± 2 V DC
B-2. Adjust
Select timing #6 (VESA 64K 1280x1024)with crosshatch pattern, adjust both horizontal and vertical
OSD’s size control to get display size within 262x196±1mm.
Adjust VR501 to get a DC 145±0.3 V to be obtained on FBT’s pin3.
Double check and make sure test points are within speci fications as defined i n following
Timing Mode Volt age Tol erance
#1 31.5 KHz 66.7V ±3%
#6 68.677 KHz 145V ±3%

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B-3. Picture Alignment
White balance alignment
Select timing #6(VESA 64K 1280x1024) with crosshatch pattern, adjust both horizontal and vertical
OSD’s size control to get di splay size within 262 x 196±1mm.
Disconnect R×G×B signal inputs, adjust OSD’s brightness control to i t’s maximum position then
adjust FBT’s G2 control VR to get a DC voltage t o be obtained on CRT socket pin #7 as defined in
following
CRT type G2 Voltage
SAMSUNG 550V+/-10V
LG 550V+/-10V
B-4. White Balance Aignment
B-5. Select timing 6 VESA 1280X1024 with full field raster pattern (cut off R, G, B) Adjust H-size 260mm V-size
195mm
B-6. Brightness and Contrast set to MAX adjust G2, has G2 Voltage to be 550V, then, adjust VR502 to get raster is
0.8fl.
Adjust G DC-bias has Y=0.8FL
BDC-biashasy=311+/-25
R DC-bias has x=281 +/- 25
Adjust Brightness to raster is 0.06fl.
B-7: Select 2 inch one-square pattern, adjust color temperature 9300Celsius degree.
Adjust GDC-GainhasY=50FL+/-2FL
BDC-biashasy=311+/-5
R DC-bias has x=281 +/- 5
B-8: Select white pattern,
Double check x=281 +/-2 5
y=311 +/-2 5
Adjust SUB-Bright to get full white pattern, Y is 105 +/-3 cd/mm
B-9:Same procedure, to get
Color temperature 6500 x=313 y=329
5000 x=345 y=359
B-10. Focus alignment
B-11. Select timing #6 (VESA 64k 1280x1024) with a 2 inch five-square pattern, adjust the OSD’ s brightness control
to get raster light output equial to 0.06 F-L then adjust OSD’ s contrast control to get 35F-L at the center of center of the
screen, select an alternating “me” pattern that fills the screen with letters that white on black then adjust FBT’ s G4
control VR to get best focus on quarter position of CRT screen

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B-12. Double check focus performance the letters must be clear, legible and uniform, if not, repeat stape 2.3.2.1 to
obtain best focus performance.
B-13. Mi sconvergence alignment
B-14. Select crosshatch pattern and then input individually input R+B and R+G signals then measure and make sure
miscongence within Center = 0. 2 mm(max.)
Zone A = 0.3 mm(max.)
Zone B = 0.4 mm(max.)
, if not, readjust 4 P and 6P on the deflection yoke to get misconvergnce within specification. Preset modes alignment
B-15. Disconnect P103 before automatic alignment or connect P103 before manual
alignment.
B-16. Turn off monitor power and plug in P103 then turn on power again to get into factory mode.
B-17. Adjust H-size/ H-phase/V-size/V-center/ pincushion/trapezoid control s…. etc., to get geometric distortion within
specification as shown in engineering specification.
B-18. If raster center can’t be adjust to get properly, P801 may sometime be necessary to reconnect in reverse direction
and then repeat step 2, 3, 4, 3 to get geometric distortion within specification.
B-19. X-ray protection test
B-20. Short P502 for 1 second at least to verify X-ray protection circuit is working properly.
B-21. Burn-in mode and power saving check
B-22. Turn off power, disconnect I/O cable and plug in P103 then turn on the power again to get into burn-in mode.
B-23. Turn off the monitor power and unplug P103 then disconnect H or V sync, turn on the power again to get into
suspend mode (power LED should indicating amber color), disconnect both H and V sync to get into off mode (power
LED should indicating amber color)

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C. Preset Timing:
C-1. Mode : 1
Horizontal Active 640 Pixels
Vertial Active 480 Pixels
Refresh 606 Hz
Sync Polarity -,- (HSync VSync)
HORIZONTAL CHAR PIX / CHAR PIX ACTUAL UNITS
Pixel Frequency 25.1750 MHz
Pixel Period 39.7219 ns
Active 640 25.4220
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Border 1 X8= 8 0.3178
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Front Porch 1 X8= 8 0.3178
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Sync Width 12 X8= 96 3.8133
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Back Porch 5 X8= 40 1.5889
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Total 800 31.7776
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Horizontal Frequency 31.4688 kHz
Bordered Video 656 26.0576
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Blanking Interval 144 5.7200
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Blank + 2*Border 160 6.3555
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VERTICAL CHAR PIX / CHAR LINES ACTUAL UNITS
Active 480 15.2532 ms
Border 8 X1= 8 0.2542 ms
Front Porch 3 X1= 3 0.0953 ms
Sync Width 2 X1= 2 0.0636 ms
Back Porch 24 X1= 24 0.7627 ms
Total 525 16.6832 ms
Vertical Frequency 59.9405 Hz
Bordered Video 496 15.7617 ms
Blanking Interval 29 0.9215 ms
Blank + 2*Border 45 1.4300 ms

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C-2. Mode : 2

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C-3. Mode : 3

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C-4. Mode : 4

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C-5. Mode : 5