Hitachi CM615ET User manual

CAUTION:
Before servicing this chassis, it is important that the service technician read the “Safety
Precautions”and“ProductSafetyNotices”inthisservicemanual.
ATTENTION:
Avantd’effectuerl’entretienduchâassis,letechniciendoitlireles«Précautionsdesécurité»
etles«Noticesdesécuritéduproduit»présentésdansleprésentmanuel.
VORSICHT:
VorÖffnendesGehäuseshatderService-Ingenieurdie„Sicherheitshinweise“und„Hinweise
zurProduktsicherheit“indiesemWartungshandbuchzulesen.
SERVICE MANUAL
MANUEL D'ENTRETIEN
WARTUNGSHANDBUCH
Data contained within this Service
manual is subject to alteration for
improvement.
Les données fournies dans le présent
manuel d’entretien peuvent faire l’objet
demodificationsenvuedeperfectionner
leproduit.
Die in diesem Wartungshandbuch
enthaltenenSpezifikationenkönnensich
zwecksVerbesserungenändern.
OCTOBER 2000
No. 0502
SPECIFICATIONSAND PARTS ARE SUBJECTTO CHANGE FOR IMPROVEMENT
CM615ET
CM615ET302
CM615ET303
CM615ET321

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1. DISPLAY ALIGNMENT
A. Times & Display Size
For all presetting mode listing in section 2.4 shall be within the limitation:
H. WIDTH 306 ± 4 mm
V. HEIGHT 230 ± 4 mm
The external control range of the data area, shall be as follows;
Max. horizontal size : overscan the screen
Min. horizontal size : ≤285mm
Max. vertical size : over the screen
Min. vertical size : ≤202 mm
B. Picture Position
For all presetting mode listing in section 2.4 shall be within the limitation:
H.PHASE SCREEN CENTER ± 3 mm
V.CENTER SCREEN CENTER ± 3 mm
The external control ranges of display for all modes listed in section 2.4
H.POSITION ≥50 mm
V.CENTER ≥25 mm
C. Linearity
The CONTRAST and BRIGHTNESS control shall be properly adjusted at 20 F-L with Full-intensity
reverse pattern, then change to crosshatch Pattern 12x10 (Hx V), the size of grid of crosshatch pattern in
every display mode shall not vary than 10%.If two line is next to each other, 5% if they are not next to
each other. The calculation formula was listed below:
Hmax-HminVmaxV min
x100% or x100%
(Hmax + Hmin) / 2 (Vmax + Vmin) / 2

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D. Geometry Distortion (All Preset Mode) :
1) The Contrast and Brightness control shall be properly adjusted at 20 F-L with full intensity reverse
pattern, then change to crosshatch pattern.
2) Pincushion distortion shall be less than H : 1.5% and V : 1.5%.
3) Barrel distortion shall be less than H : 1.5% and V : 1.5%.
4) Trapezoid and parallelogram distortion shall be less than H : 1.5% and V : 1.5%.
5) Distortion of four corners shall be less than 3mm x 3mm.
6) Parallelogram distortion shall be less than 2.0%
7) Tilt distortion shall be less than 1/2 degree when facing east and less than 1 degree when turning
around 360 degree.
8) Tilt distortion shall be less than 2 mm when facing east and less than 1 degree when turning around
360 degree The measurement of tilt is defined to measure the vertical axis with respect to the bezel,
the absolute value of the difference between the extreme left and right measurement of the center
horizontal line.
E. Alignment Procedure
E-1. Brightness Adjust:
Adjust the VR980, have the +15VS By 14.9V±0.1V (The voltage of the C944) in TIMING 1.
Check below items.
The voltage of C949 : 179 ±3V
C947 : 75 ±2V
C946 : 44 ±1.5V
C940 : 8.4 ±0.4V
P990 : 12 ±0.3V
Short-Circuit protection function check.
The power source is 230VAC input.
When short the C944, all output voltage should be shut down and unlatch.
When recover normal condition, all output voltage should recover automatically.

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E-2. Light output adjust
Select Timing 1, preset BRI. And CONT. to max. position.
Adjust G2 to get G2 = 550V ±10V
Adjust VR803 to get light output = 0.6FL ~ 0.5FL
Select Timing 2, adjust VR405 to get pattern over scan. (H SIZE 100%)
F. White Balance Adjustment (9300°as major temperature) Low light
adjust
9300°6500°5000°
x = 0.283 ±10 x = 0.313 ±10 x = 0.324 ±10
y = 0.297 ±10 y = 0.329 ±10 y = 0.342 ±10
Y = 0.6 ~ 0.8FL Y = 0.6 ~ 0.8FL Y = 0.6 ~ 0.8FL
Select Timing 6, adjust BRI. And CONT. to max. disconnect R. G. B. signals, adjust R/B BAIS to 100 scale
(OSD then solowly adjust G BAIS to 100 scale adjust VR803 to get light output = 0.6 ~ 0.8FL for 9300,
repeat above steps for 6500 and 5000 R/B GAIN setting to get raster color temperature within specified,
finally, adjust BRI to get raster = 0.06FL.
High light adjust
9300°6500°5000°
x = 0.283 ±10 x = 0.313 ±10 x = 0.324 ±10
y = 0.297 ±10 y = 0.329 ±10 y = 0.342 ±10
Y = FL Y = FL Y = FL
Select Timing 4, measure 2 "square, set CONT. to Max, position and SUB-CONT to 127, R/B GAIN to
200, G
GAIN to 200, adjust SUB-CONT to get light output = 50 FL for 9300, repeat above steps for 6500
and
5000 R/B GAIN setting to get color temperature within specified.
3. Select Timing 3 with full white pattern adjust OSD-ABL (SUB BRIGHTNESS) to get full white light
output = 30 ±1 FL.
G. Focus Adjustment
G-1. Adjust brightness, have the brightness of raster be 0.06FL and contraset be 35FL in timming 6.
G-2. Adjust the G4a and G4b of theFBT, have focus be in the best condition on the 1/4 diagonal of
screen in timing 5.

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H. Convergence Adjustment
Input R+B and R+G signals, make sure convergence within specified (if not 4 pole and 6 pole). A zone =
0.3MM., B zone 0.4MM. (X) < 0.4MM, (Y) < 0.4MM.
NOTE : 1 Aarea = 230mm (circle)
2 B area = 306 x 230 mm
I. Presetting Modes Adjustment
There are totally 12 preset modes, individual adjust is needed.
H-SIZE adjust : adjust control key to get H-SIZE = 306 ±2mm.
H-CENTER adjust : adjust control key to get center within ±2mm
V-SIZE adjust : adjust control key to get V-SIZE = 230 ±2mm
V-CENTER adjust : adjust control key to get center within ±2mm
Geometric adjust : adjust control key to get minimize distortion.
H-linearity check : check and make sure linearity meet spec..
(CROSS HATCH PATTERN 10X8)
2(MAX -MIN)
X100%
MAX + MIN
Any : <10%
Adjacent : <5%
V-linearity check : check and make sure linearity meet spec.
2(MAX -MIN)
X100%
MAX + MIN
Any : <10%
Adjacent : <6%
Geometric check : check and make sure geometric meet spec.
Get into OSD select EE-USER item, press ENTER till OSD disappear then turn off power, disconnect JP1,
turn on power again, make sure all of the alignment parameters has been stored properly, make H-SIZE
adjust range can OVER SCAN and -5%, PHASE adjust range >15mm, V-SIZE adjust range can OVER
SCAN and -6%, V-CENTER adjust range >20mm and make sure TILT adjust work properly.

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J. Power Adjustment
J-1. Adjustthe VR980, have the +15Vs be 15.3v ± 0.1v (the voltage of the C944) in timing 1.
J-2. Checkbelow items the voltage of C949 : 179
± 3v
J-3. Short-circuit protection function check
when short the C944, all output voltage should be shut down and unlatch
J-4. Side Pincushion, Tilt and GeometryDistortion Adjustment
1. Input timing 1, adjust the display be normal position and size.
2. Adjustfront control key to get the bestpincushion distortion and tilt.
3. SelectP502 and adjust VR402~VR404 to get the best geometrydistortion.
J-5.Focus Adjustment
1. Input timing 1, EXT.BRIGHTNESS move to center position. UseEXT.CONTRAST set the
brightnessto 25FL.
2. Adjust Focus VR (mounting on F.B.T), to get best focus.
C947 : 75
±±±± 2v
C946 : 44
±±±± 1.5v
C940 : 8.4
±±±± 0.4v
the power source is 230vac input
when recover normal condition, all output voltage should recover automatically.

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J-6. Preset Timing Adjustment
1. Input each PRESET MODE timing, and use front control key adjust the display to the normal position
and size, and wait for 5 seconds.
2. Switch to next timing repeat 1 process. Until every PRESET MODE timing have been adjusted.
J-7. Timing And Pattern
Timing mode pattern.mdnm/
1 VESA 68.6k CROSS HATCH
2 VESA 68.6K 2" SQUARE
3 VESA 68.6K FULL WHITE
J-8. Power Saving Function Check
The power source is 230Vac input
When remove the sync signal, the monitor should enter suspend mode and then off mode.
When power saving, the power consumption of monitor should be less than: suspend mode 8w off mode
The monitor recovering time from suspend mode or off mode to on mode should be less than 5 seconds.
TABLE 1
TIMING MODE PATTERN
1. 64K 51 CROSSHATCH
2. 37.8K/60HZ 51 CROSSHATCH
3. 60K Full-white
4. 60K 5×2″squares
5. 68K “me”
6. 68K 5×2″squares

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PRESETTING MODES TABLE2
D:display B:backporc
h P:pulse F:front
1 VGA 640
350 25.175 P/N 31.469 70.087 31.778 14.268 25.422 11.122 907 1.875 3.813 0.064 636 1.207
2 IBM
VGA 640 480 25.175 N/N 31.469 59.940 31.778 16.683 25.422 15.253 907 1.0169 813 0.064 636 0.318
3 VESA
640
480 31.5 N/N 37.5 75 26.667 13.333 20.317 12.8 3.81 0.427 2.032 0.08 0.508 0.027
4 VESA
640
480 36 N/N 43.269 85.008 13.111 11.764 17.778 11.903 2.222 0.578 1.556 0.069 1.556 0.023
5 IBM
VGA 720 400 28.321 N/P 31.468 70.085 31.468 70.085 31.778 14.268 25.422 12.711 1.907 1.0804 0.636 0.413
6 VESA
800
600 40 P/P 37.879 60.317 36.4 16.579 20 15.84 2.2 0.607 3.2 0.106 1 0.026
7 VESA
800
600 49.5 P/P 46.875 75 21.333 13.333 16.162 12.8 3.232 0.448 1.616 0.064 0.323 0.021
8 VESA
800
600 56.25 P/P 53.674 85.061 18.631 11.756 14.222 11.179 2.702 0.503 1.138 0.056 0.569 0.019
9 VESA IBM
XGA
1024
764 65 N/N 48.363 60.004 20.677 16.666 15.754 15.88 2.462 0.6 2.092 0.124 0.369 0.063
10 VESA 1024
768 78.75 P/P 60.023 75.029 16.66 13.328 13.003 12.795 2.235 0.466 1.219 0.05 0.203 0.017
11 VESA 1024
768 94.5 P/P 68.677 84.997 14.561 11.765 10.836 11.183 2.201 0.524 1.016 0.044 0.508 0.015
12 VESA 1152
864 108 P/P 67.5 75 14.815 13.333 10.667 12.8 2.37 0.474 1.185 0.044 0.593 0.15
13 VESA 1280
1024 108 P/P 63.981 60.02 15.63 16.661 11.852 16.005 2.296 0.594 1.037 0.047 0.444 0.016

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Fig. 2
Fig. 3

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2. CONTROL AND CONNECT LAYOUT
Main PCB

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B. Video PCB

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C. Pin Assignment
C-1. Connect Function
VR501 : H-CENTER VR
P701 : TILT CONN
P8 : CANCEL COIL CONN
JP1: PRESET CONN
P902 : DEGAUSSING COIL CONN
P703 : X-RAYTEST PAD
-P302 P303 P301 P5
HFLB Vout DSUB9 DDC-SCL
GND EEP-SCL R-IN DDC-SDA
G1 EEP-SCL GND GND
6.3V H-OUT B-IN V-SYNC
5V GND GND H-SYNC
75V-- G-IN --
12V-- GND --
CONTRAST-- -- --
1
2
5
3
4
6
8
7

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3. Power Supply Portion

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4. OPERATION THEOREM
A. Power Supply:
Transfer AC source to DC source that supply all the circuit power. It includes:
(1) +12V: For video pre-amp circuit, parts of horizontal and vertical deflection circuit.
(2) +180V: For deflection and H.V circuit
(3) +7.5V: For CRT heater and u-P power.
(4) +75V: For video AMP. Circuit.
(5) +42V: For vertical deflection and Horizontal predriver .
(6) +16V: For vertical preampifier
B. Deflection:
Produce YOKE deflection current of horizontal and vertical, CRT H.V and bias that makes screen raster.
C. Video
Amplify the video signal and add the signal to the cathode of CRT to produce video on the screen.
D. Digital Controllor
With the EEPROM and PROGRAM, the micro-processor(u-P) control all the picture performance.
From the key control, the user can change the H-size, V-size, R-gain.…etc.

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E. Function Block Diagram

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F. Power Supply
F-1. Rectifier And Filter Ckt:
The 90Vac-265Vac input line voltage is rectified by D901- D904, and smoothed by C906 to provide
DC operating voltage for the circuit.
F-2. Flyback And Pwm Ckt :
When power is initially applied to the circuit,C909 charges through R903, Q902.When the voltage
across C909 reaches a level of 16V, U901 is enabled, turning on Q901 and turning off Q902 to
complete start-up action.
During the On-time of Q901, energy is stored in T900. At this time the polarity of the output windings
is such that all output rectifiers are reverse biased and no energy is transferred. Primary current is
sensed by R914 and compared to a DC level that is determined by voltage feedback. When this
level is reached, Q901 is turned off and the polarity of all T900 windings reverses , forward biasing
the output rectifiers. All the energy stored is now transferred to the output capacitors. Many cycles
of this store/release action are needed to charge the outputs to their respective voltages.
The voltage across C949 is fed through a voltage divider R984,R985,R986, R987 and VR980 to the
error amplifier U980 and compared to an internal 2.5V reference ,then determine the feed back
level of U901 PIN1.
F-3. Snubber Ckt:
Energy stored in the leakage inductance of T900 cause a voltage spike which be added to the
normal reset voltage across T900 when Q901 turn off. The clamp consisting of D905, R904 and
C907 limits this voltage excursion from exceeding the Vds rating of Q901. In addition, a turn off
snubber made up of D906, R905 and C908 keeps power dissipation in Q901 low by delaying the
voltage rise until drain current has decreased from its peak value. This snubber also damps out any
ringing which may occur due to parasitic.
F-4. Synchronized Ckt:
The oscillator frequency is defined by R912 , C920. The equation is approximately : Fosc=1.8/
(R912*C920). The external signal “SYN+& SYN−”
that comes from horizontal circuit T802 can synchronize the working frequency of power circuit Via
ZD903,R918,R919 and R916.
F-5. Power Saving Ckt:
The monitor has ON, Suspend/Standby and OFF states.The monitor enters Suspend/Standby
mode if either V-sync or H-sync signals are removed.When the machine in the Suspend/Standby
State, PS1 should be low to turn off +15Vs. In this state, input power should be less than 15W and
D960 LED illuminate yellow. The monitor enters OFF mode if both H-sync and V-sync are removed.
When in the OFF State, PS1 and PS2 should below simultaneously to turn off +15Vs and +8.3Vs
outputs. In this state, input power should be less than 5W and D960 LED illuminate amber.

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F-6. Degauss Ckt
The DEGU signal which comes from micro-p to control degauss coil act or not.
When DEGU is high, Q950 will be saturated to make RL901 working, AC line provides
a degaussing current to degauss coil.
F-7. OVERLOAD PROTECTION CKT
The primary current flows through the current sensing resistor R914. The voltage drop on R914 will
be rectified by D927 and keep a dc level on C927 that is dependent on the output power. When this
DC level reach the trigger voltage of Q920 , the pin1 of U901 goes low and the power stage is
immediately switched off.
F-8. BROWN – OUT CKT
When the input voltage down below the setting level (85Vac-75 Vac), Q904 will be supplied a trigger
voltage to make Q920 turn on ,and this time, power supply shall be shut down.
G. Deflection
G-1. Sync Rpocessor:
H-sync & V-sync or input to U1(u-P), then u-P output the H-out & V-out to
U401(TDA4858).
G-2. Hor. Processor & Vert. Pre-Amp
Fig.2 is the block diagram of IC TDA4858.
 Hor . processor
The H-out that come from u-P will input to the pin 15 of U401,it will be compared
with the oscillator sawtooth voltage by the PLL1(pin 26) phase detector, After that, it will be
compared again with the flyback pulse (pin 1) by the PLL2. The PLL2 detector thus compensates
for the delay in the external horizontal deflection circuit by adjusting the phase of the HDRV(pin 7)
output pulse.
 B+control
The U401 pin5 to pin3 is operation Amprifier from pin11 EW DRV parabla amplitude DC,H-Size
and Trapezium correction wave from connection ,pin6 is forward PWM output ,driver the
Q420,Q422 all mode B+is 180V
 Vert. Pre-am
Vertical oscillator will be trigged by V-out (pin 14) .It is availvable to get sawtooth waveform in pin 24.
V-center, V-amp and V-linearity can be adjusted in pin 17, 18 and 19. The vertical output driver is
come from pin 12 and 13.

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G-3. Vertical Output
IC U601(TDA 4866) is the vertical amp IC, the output pin6 connect to the YOKE .The sawtooth
current float across the YOKE to make vertical deflection. Fig.3 is the block diagram of IC TDA4866
G-4. Horizontal Driver Circuit
The driver pulse that come from U401 pin7 drive Q417,Q416,TO Q503,then transfomer T501
convert driver pulse to driver current to drive horizontal output transistor Q504.
G-5. Horizontal Output Stage
31K→35K→37K→43K→46K→53K→60K→64K→68K
SW4
C515
SW3
C539
SW2
C521
SW1
C520
L:ACTION
L
L
H
L
L
L
L
L
L
L
L
L
H
H
H
H
H
H
H
H
H
H
L
L
L
H
H
H
H
H
H
H

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H. Flyback Transformer
In the primary of F.B.T ,there is about 900Vpp in the LC resonant interval,
It convert to the secondary of F.B.T to produce about 26KV for CRT anode voltage.
The other bias for CRT IS G4.G3(4∼8KV),G2(0∼1000V)and G1(-160V)

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H-1. . BLOCK DIAGRAM