Warnings and Cautions............................................................................................................................. 5
Safety Check Out ..................................................................................................................................... 6
1-2. Service Position................................................................................................................................. 7
1-3. A & D Board Removal........................................................................................................................ 8
6. Electrical Parts List ....................................................................................................................................... 29
— 3 —
HMD-A240
POWER MANAGEMENT
The power saving mode complies with the VESA Display Power Management Signaling standard. Each state of power management shall be activated
by the host computer terminating the appropriate sync signals. Blanking the video must precede termination of the sync signals. The elapsed time
counter shall also be controlled by the host computer. Reactivation of the monitor shall be accomplished from the host computer by re-establishing the
normal sync signal.
Power consumption Screen Horizontal Vertical Power Recovery time Indicator
mode (video) sync signal sync signal consumption
1 Normal operation active yes yes < 100 W -- Green
2 Active-off (3rd mode) blank no* no* < 3 W Approx. 10 sec. Amber
3 Power-off -- -- -- 0 W (approx) -- Off
* In this mode, the signal will appear in one of three ways: The Horizontal Sync Signal alone off, the Vertical Sync Signal
alone off, or both signals off.
SELF DIAGNOSIS FUNCTION
When a failure occurs, the STANDBY/TIMER lamp will ß ash a set number of times to indicate the possible cause of the problem. If there is more than
one error, the lamp will identify the Þ rst of the problem areas.
Status
1
Failure 1
2
Failure 2
3
Failure 3
4
Aging/Self Test
Area of Failure
HV or +B
H Stop, V Stop or S Correction FET Failure
ABL
Amber (0.5 second) / Off (0.5 second)
Amber (1.5 second) / Off (0.5 second)
Amber (0.5 second) / Off (1.5 second)
Amber (0.5 second) / Off (0.5 second)/
Green (0.5 second) / Off (0.5 second)
LED Indication
TIMING SPECIFICATION
PRIM E
MODE
MODE123456789
RESOLUTION 640 X 480 640 X 480 720 X 400 800 X 600 800 X 600 832 X 624 1024 X 768 1024 X 768 1280 X 1024
CLOCK25.1753628.32249.556.2557.28378.7594.5108
HORIZONT AL
H. FREQ31.46943.26931.46946.87553.67449.72560.02368.67763.981
H. TOTAL31.77823.11131.77721.33318.63120.11116.66014.56115.630
H. BLK6.3565.3336.3555.1724.4095.5863.6573.7253.778
H. FP0.6361.5560.6360.3230.5690.5590.2030.5080.444
H. SYNC3.8131.5563.8131.6161.1381.1171.2191.0161.037
H. BP1.9072.2221.9073.2322.7023.9102.2352.2012.296
H. ACTIV25.42217.77825.42216.16214.22214.52413.00310.83611.852
VERTI CAL
V. FREQ59.94085.00870.08775.00085.06174.55075.02984.99760.020
V. TOTAL16.68311.76414.26813.33311.75613.41413.32811.76516.661
V. BLK1.4300.6701.5570.5330.5780.8650.5330.5820.656
V. FP0.3180.0230.3810.0210.0190.0200.0170.0150.016
V. SYNC0.0640.0690.0640.0640.0560.0600.0500.0440.047
V. BP1.0490.5781.1120.4480.5030.7840.4660.5240.594
V. ACTIV15.25311.09312.71112.80011.17912.54912.79511.18316.005
SYNC
EXT (H/V) / POLARITYYESYE SYESYESYESYESYE SYESYES
EXT (CS) / POLARITYNONONONONONONONONO
INT (G)NONONONONONO NO NO NO
SERRATIONNONONONONONONONONO
SYNC LEVELTTLTTLTTLTTLTTLTTLTTLTTLTTL
VIDEO
VIDEO LEVEL0.70.70.70.70.70.70.70.70.7
SET UP 000000 0 0 0
— 4 —
HMD-A240
WARNINGS AND CAUTIONS
CAUTION
Short circuit the anode of the picture tube and the anode cap to the metal chassis, CRT shield, or carbon painted on the CRT, after
removing the anode.
WARNING!!
An isolation transformer should be used during any service to avoid possible shock hazard, because of live chassis. The chassis of this
receiver is directly connected to the AC power line.
!SAFETY-RELATED COMPONENT WARNING!!
Components identiÞ ed by shading and ! mark on the schematic diagrams, exploded views, and in the parts list are critical for safe
operation. Replace these components with sony parts whose part numbers appear as shown in this manual or in supplements published
by sony. Circuit adjustments that are critical for safe operation are identiÞ ed in this manual. Follow these procedures whenever critical
components are replaced or improper operation is suspected.
ATTENTION!!
Apres avoir deconnecte le cap de l’anode, court-circuiter l’anode du tube cathodique et celui de l’anode du cap au chassis metallique de
l’appareil, ou la couche de carbone peinte sur le tube cathodique ou au blindage du tube cathodique.
AÞ n d’eviter tout risque d’electrocution provenant d’un chássis sous tension, un transformateur d’isolement doit etre utilisé lors de tout
dépannage. Le chássis de ce récepteur est directement raccordé à l’alimentation du secteur.
! ATTENTION AUX COMPOSANTS RELATIFS A LA SECURITE!!
Les composants identiÞ es par une trame et par une marque ! sur les schemas de principe, les vues explosees et les listes de pieces
sont d’une importance critique pour la securite du fonctionnement. Ne les remplacer que par des composants sony dont le numero
de piece est indique dans le present manuel ou dans des supplements publies par sony. Les reglages de circuit dont l’importance est
critique pour la securite du fonctionnement sont identiÞ es dans le present manuel. Suivre ces procedures lors de chaque remplacement
de composants critiques, ou lorsqu’un mauvais fonctionnement suspecte.
— 5 —
SAFETY CHECK-OUT
HMD-A240
After correcting the original service problem, perform the following
safety checks before releasing the set to the customer:
1. Check the area of your repair for unsoldered or poorly soldered
connections. Check the entire board surface for solder splashes and
bridges.
2. Check the interboard wiring to ensure that no wires are “pinched” or
touching high-wattage resistors.
3. Check that all control knobs, shields, covers, ground straps, and
mounting hardware have been replaced. Be absolutely certain that
you have replaced all the insulators.
4. Look for unauthorized replacement parts, particularly transistors,
that were installed during a previous repair. Point them out to the
customer and recommend their replacement.
5. Look for parts which, though functioning, show obvious signs of
deterioration. Point them out to the customer and recommend their
replacement.
6. Check the line cords for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
7. Check the B+ and HV to see if they are speciÞ ed values. Make sure
your instruments are accurate; be suspicious of your HV meter if
sets always have low HV.
8. Check the antenna terminals, metal trim, “metallized” knobs,
screws, and all other exposed metal parts for AC leakage. Check
leakage as described below.
Leakage Test
The AC leakage from any exposed metal part to earth ground and from all
exposed metal parts to any exposed metal part having a return to chassis,
must not exceed 0.5 mA (500 microamperes). Leakage current can be
measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA
2. A battery-operated AC milliammeter. The Data Precision 245 digital
3. Measuring the voltage drop across a resistor by means of a VOM
How to Find a Good Earth Ground
A cold-water pipe is a guaranteed earth ground; the cover-plate retaining
screw on most AC outlet boxes is also at earth ground. If the retaining
screw is to be used as your earth ground, verify that it is at ground
by measuring the resistance between it and a cold-water pipe with an
ohmmeter. The reading should be zero ohms.
If a cold-water pipe is not accessible, connect a 60- to 100-watt troublelight (not a neon lamp) between the hot side of the receptacle and the
retaining screw. Try both slots, if necessary, to locate the hot side on the
line; the lamp should light at normal brilliance if the screw is at ground
potential (see Figure B).
WT-540A. Follow the manufacturers’ instructions to use these
instructions.
multimeter is suitable for this job.
or battery-operated AC voltmeter. The “limit” indication is 0.75
V, so analog meters must have an accurate low voltage scale.
The Simpson’s 250 and Sanwa SH-63TRD are examples of
passive VOMs that are suitable. Nearly all battery-operated digital
multimeters that have a 2 VAC range are suitable (see Figure A).
Parts on Set
.15 µF
1.5 K Ω
AC
Voltmeter
(0.75 V)
Figure A. Using an AC voltmeter to check AC leakage.Figure B. Checking for earth ground.
— 6 —
1-1. CABINET REMOVAL
2
2
1
SECTION 1: DISASSEMBLY
Remove (4) Screws (+BVTP 4 x 16)
Release top claws - Insert the tip of a ß athead
HMD-A240
1
2
screwdriver approximately 0.25" to unlock the
claw. Gently lift up and then back to remove
the cabinet.
1-2. SERVICE POSITION
Gently wiggle the A board back and forth to unplug
1
it from the Neck Assembly.
Remove all necessary connections and rotate the
2
D Board and rest it on its side to expose the bottom.
Be sure to reconnect all wires.
Fabricate a temporary ground wire with a male
3
stakon connector on one end and an alligator clip
on the other.
Reconnect ground as shown below.
4
1
2
4
— 7 —
1-3. A & D BOARD REMOVAL
HMD-A240
3
2
Remove (1) screw (+BVTP 3 x 8) from the cable holder
1
at the rear of the chassis base to release the cable.
Remove (2) screws (+BVTP 3 x 8) from the rear of the D
2
Board and remove the rear of the chassis base.
Remove remaining (7) screws (+BVTP 3 x 8) from the D
3
Board. Lift the board up and out to remove.
Remove the shield cover from the A board.
4
5
4
1
Gently wiggle the A board back and forth, and pull it to
5
remove.
— 8 —
1-4. PICTURE TUBE REMOVAL
Place the unit face down on a cushion to avoid
1
scratching.
Remove the anode cap.
2
Remove (4) screws (Screw (5) Tapping) from
3
the CRT.
Remove the A board.
4
Remove the neck assembly.
5
Remove the deß ection yoke.
6
Remove (2) screws (BVTP 4 x 16) from the
7
base assembly and slide out to remove.
HMD-A240
8
Remove the demagnetization coil.
ANODE CAP REMOVAL
WARNING: High voltage remains in the CRT even after the power is disconnected. To avoid electric shock, discharge CRT before attempting to remove
the anode cap. Short between anode and coated earth ground strap of CRT.
NOTE: After removing the anode cap, short circuit the anode of the picture tube and the anode cap to either the metal chassis, CRT shield, or carbon
painted on the CRT.
REMOVAL PROCEDURES
c
b
a
AnodeButton
Turn up one side of the rubber cap in the
direction indicated by arrow
a
.
Use your thumb to pull the rubber
cap Þ rmly in the direction indicated
by arrow
.
b
When one side of the rubber cap separates from
the anode button, the anode cap can be removed
by turning the rubber cap and pulling it in the
direction of arrow
c
.
HOW TO HANDLE AN ANODE CAP
1. Do not use sharp objects which may cause damage to the surface of the
anode cap.
2. To avoid damaging the anode cap, do not squeeze the rubber covering too
hard. A material Þ tting called a shatter-hook terminal is built into the rubber.
3. Do not force turn the foot of the rubber cover. This may cause the shatter-hook
terminal to protrude and damage the rubber.
— 9 —
SECTION 2: SAFETY RELATED ADJUSTMENTS
HMD-A240
When replacing parts shown in the table below, the following
operational checks must be performed as a safety precaution
against X-ray emissions from the unit.
Part Replaced ( )
HV ADJ
HV Regulator
Circuit
HV HOLD
DOWN Circuit
Beam Current
Protector Circuit
Allow the unit to warm up for one minute prior to checking the
5. ConÞ rm that the voltage is within the voltage range shown below:
Standard voltage: 26.0 +0.3, -0.5 kV
6. When replacing components identiÞ ed by
the High Voltage.
7. Verify the High Voltage as shown above (26.0 +0.3, -0.5 kV) is
within speciÞ cation. If not, set H. SIZE data at minimum (-127)
and then adjust RV501 on D Board (Adjustment target = 26.0 ±
0.2 kV).
8. After adjusting the High Voltage within speciÞ cation, put the RV
cover on RV501 as shown below and apply sufÞ cient amount of RTV
around RV501.
Y
, make sure to recheck
2-2. HV PROTECTOR CIRCUIT CHECK
1. ConÞ rm that the voltage between cathode of D517 and GND is
more than 27.0 VDC.
2. Using an external DC Power supply, apply the volt age shown below
between cathode of D517 on D Board and GND, and conÞ rm that
the HV Hold-Down circuit works (Raster disappears). Apply DC
Voltage: Less than 35.9 VDC.
Check Condition
• Input voltage: 120 ± 2 VAC
• Input signal: (fH =69 kHz), White Cross Hatch
• Controls: CONT (max) & BRT (center)
• B+ Voltage: 179 ± 3.0 VDC
2-3. BEAM PROTECTOR CHECK
(SOFTWARE LOGIC)
1. Using an external current source, apply < 1.55mA between pin 11
of FBT (T501) and GND, and conÞ rm that the raster fades out.
Check Condition
• Input voltage: 120 ± 2 VAC
• Input signal : (fH = 69 kHz), White Cross Hatch
• Controls: CONT (max) & BRT (center)
2-4. B+ VOLTAGE CHECK
1. Input white cross hatch (fH = 69 kHz) signal.
2. CONT (max) & BRT (center).
3. Input voltage: 110 ± 10 VAC.
Note: Use NF power supply or make sure that dis tortion factor is
3% or less.
4. ConÞ rm that the voltage is within the range shown below:
Standard voltage: 179 ± 3.0 VDC
104
RV501
— 10 —
HMD-A240
SECTION 3: ADJUSTMENTS
Connect the communication cable of the connector located on the D Board on the monitor. Run the service software and then follow the instructions.
3-702-691-01
1
1-690-391-21
A-150-919-A
2
Interface Unit
3
Connector Attachment
IBM at Computer
as a Jig
D-Sub
(9 Pin [female])
* The Parts above ( ) are necessary for DAS Adjustment.
Allow a 30 minute warm-up period prior to making the following
adjustments.
Mini Din
(8 Pin)
4 Pin
-
1
3
3-1. LANDING ROUGH ADJUSTMENT
1. Display the all white pattern.
2. Adjust the contrast to maximum value.
3. Display plain green pattern.
4. Slide the DY back and roughly adjust the plain green pattern with
the purity magnet so that it is centered on the screen.
5. Adjust HCENTER by HCENTER Volume (RV502 on D Board).
6. Moving the DY forward, adjust so that an entire screen be comes
pure green.
7. Adjust the DY tilt and lightly tighten the DY screw.
To BUS CONNECTOR
4 Pin
13. Adjust V.Key (= H.Trapezoid) with H.TRP VR so that [a] is equal to
14. If the corner landing is out of speciÞ cation, use a disk magnet for
15. If disk magnets were used, perform an auto degauss.
16. Remove the wobbling coil and sensor.
17. Fix the purity magnet on DY with white paint.
4 Pin
[b] (See Section 3-4.).
the landing correction.
3-3. CONVERGENCE ROUGH ADJUSTMENT
1. Enter the white crosshatch signal.
2. Roughly adjust the horizontal (H.STAT) and vertical (V.STAT)
convergence at four-pole magnet.
3. Roughly adjust HMC and VMC at six-pole magnet.
3-2. LANDING FINE ADJUSTMENT
1. Place the monitor in the Helmholtz coil.
2. Set TLH plate to zero position.
3. Display plain green pattern.
4. Degauss CRT face and iron parts with degauss equipment or handdegausser.
5. Perform auto degauss.
6. Attach a wobbling coil to the speciÞ ed position of CRT neck.
7. Put the sensor of landing checker to CRT face.
8. Adjust purity, DY position and DY tilt.
9. Tighten DY screw.
10. Perform auto degauss.
11. Adjust top and bottom pin by pitching DY up and down with two
wedges so that [a] is equal to [b].
[a]
[b]
12. Adjust top and bottom pins to zero with TB. H.PIN VR. Also, V.SIZE
should be adjusted at the same time becasue it is changed by TB.
H.PIN VR.
— 11 —
3-4. CONVERGENCE AND V. KEY (H. TRP)
FINE ADJUSTMENT
H-TRP VR
Purity
6-pole
Mg
Magnet
4-pole
Mg
Neck Ass'y
A Board
1. Display crosshatch pattern with green lines and black Þ eld.
2. Adjust V. Key (=H. Trapezoid) with H.TRP VR so that [a] is equal
to [b].
[a]
3. Adjust the TB Pin with TB Pin VR.
TLV VR
TLH Plate
XCV VR
CRT
DY
YCV VR
TB Pin VR
[b]
HMD-A240
TB Pin Movement
4. Adjust V.SIZE with "VSIZE".
5. Change "CONV_SW" to "0" and "MCR2" to "153".
6. Display crosshatch pattern with red and blue lines and black Þ eld.
7. Adjust H.STAT and V.STAT with 4 pole magnet. Use 4 pole magnet,
not "HSTAT" and "VSTAT".
4 Pole Magnet
1
2
1
2
R
1
B
R
2
1
2
R
1
2
R
B
B
R
B
B
12
R
B
14. Adjust XCV with XCV VR.
XCV Movement
15. Adjust YCH with YCH VR.
YCH Movement
R
16. Adjust V.TILT with TLV VR.
TLV Movement
R
B
B
R
B
R
B
8. Display crosshatch pattern with white lines and black Þ eld.
9. Adjust HMC and VMC with 6 pole magnet.
6 Pole Magnet
2
G
1
2
G
1
10. Display crosshatch pattern with red and blue lines and black Þ eld.
11. If necessary, repeat steps 5-8.
12. Change "CONV_SW" to "6".
13. Adjust H.TILT with TLH plate.
TLH Movement
BB
R
R
17. If necessary, repeat steps 3-14 to make the optimum condition for
the entire screen.
18. Fix 4-pole magnet, 6-pole magnet, TLH plate and XCV VR with
white paint.
Zero Position Neck Ass'y
Purity
4-Pole Mg
6-Pole Mg
3-5. VERTICAL AND HORIZONTAL POSITION
AND SIZE SPECIFICATION
a
f
0kHz
H
a
2.0 mm
A
B
b
2.0 mm
234 312
b
f
H
BA
60kHz
2.4 mm
2.4 mm
— 12 —
HMD-A240
3-6. FOCUS ADJUSTMENT
1. Adjust Focus (V) and Focus (H) for optimum focus.
Focus (V)
Focus (H)
3-7. DIGITAL CONVERGENCE ADJUSTMENT
Convergence (Low) Mode
1. Adjust the H.STAT and V.STAT with "HSTAT" and "VSTAT".
2. Change "CONV_SW" to "7".
A. Horizontal Convergence
CBH-T-LO
MBH-T-L-LO
9
17
YBH-T-LO
5
CBH-T-R-LO
10
18
MBH-T-R-LO
Convergence (High) Mode
1. Adjust the H.STAT and V.STAT with "HSTAT-HI" and "VSTAT-HI".
A. Horizontal Convergence
YBH-T-HI
5
HSTAT-HI
6
YBH-B-HI
CBH-T-R-HI
10
18
MBH-T-R-HI
2
APH-R-HI
20
MBH-B-R-HI
12
CBH-B-R-HI
CBH-T-HI
MBH-T-L-HI
APH-L-HI
MBH-B-L-HI
CBH-B-L-HI
9
17
1
19
11
Adjust each misconvergence point in sequence.
B. Vertical Convergence
V STAT-T-HI
7
V STAT-HI
8
V STAT-B-HI
14
CCV-T-R-HI
22
MCV-T-R-HI
4
XBV-R-HI
24
MCV-B-R-HI
16
CCV-B-R-HI
CCV-T-L-HI
MCV-T-L-HI
XBV-L-HI
MCV-B-L-HI
CCV-B-L-HI
13
21
3
23
15
APH-L-LO
MBH-B-L-LO
CBH-B-L-LO
1
HSTAT
19
11
6
YBH-B-LO
2
APH-R-LO
20
MBH-B-R-LO
CBH-B-R-LO
12
Adjust each misconvergence point in sequence.
B. Vertical Convergence
CCV-T-L-LO
MCV-T-L-LO
XBV-L-LO
MCV-B-L-LO
CCV-B-L-LO
13
21
3
23
15
V STAT-T-LO
7
V STAT
8
V STAT-B-LO
14
CCV-T-R-LO
22
MCV-T-R-LO
4
XBV-R-LO
24
MCV-B-R-LO
16
CCV-B-R-LO
Adjust each misconvergence point in sequence.
3. Repeat the procedure of A and B so that the convergence of the
entire screen is within the speciÞ cation.
Adjust each misconvergence point in sequence.
2. Repeat the procedure of A and B so that the convergence of the
entire screen is within the speciÞ cation.
3. Change "MCR2" to "170".
3-8. CONVERGENCE SPECIFICATION
B
A
312 mm
A Zone:
Primary Mode Others
234 mm
H: < 0.25 mm H: < 0.3 mm
V: < 0.25 mm V: < 0.3 mm
B Zone:
Primary Mode Others
H: < 0.3 mm H: < 0.4 mm
V: < 0.3 mm V: < 0.4 mm
— 13 —
4-1. CIRCUIT BOARDS LOCATION
HMD-A240
SECTION 4: DIAGRAMS
The components identiÞ ed by shading and ! symbol are critical for safety. Replace
only with part number speciÞ ed.
A Board
J Board
H Board
D Board
4-2. PRINTED WIRING BOARD AND
SCHEMATIC DIAGRAM INFORMATION
All capacitors are in µF unless otherwise noted. pF : µµF 50WV or less
are not indicated except for electrolytics and tantalums.
All electrolytics are in 50V unless otherwise speciÞ ed.
All resistors are in ohms. kΩ=1000Ω, MΩ=1000kΩ
Indication of resistance, which does not have one for rating
electrical power, is as follows: Pitch : 5mm
Rating electrical power :
1
/
W in resistance, 1/
4
W and 1/
10
W in chip resistance.
8
: nonß ammable resistor.
: fusible resistor.
: internal component.
: panel designation and adjustment for repair.
All variable and adjustable resistors have characteristic curve B, unless
otherwise noted.
Readings are taken with a color-bar signal input.
Readings are taken with a 10MΩ digital multimeter.
Voltages are DC with respect to ground unless otherwise noted.
Voltage variations may be noted due to normal production tolerances.
All voltages are in V.
S : Measurement impossibillity.
: B+line.
: B-line (Actual measured value may be different).
: signal path (RF).
Circled numbers are waveform references.
1
/
W
4
The symbol
side of the board. Replace only with fuse of the same rating as marked.
Les composants identiÞ es per un trame et une marque
securite. Ne les remplacer que par une piece portant le numero speciÞ e.
Le symbole indique une fusible a action rapide. Doit etre remplace par une
fusible de meme yaleur, comme maque.
indicates a fast operating fuse and is displayed on the component
!
sont critiques pour la
The components identiÞ ed by X in this basic schematic diagram
have been carefully factory-selected for each set in order to
satisfy regulations regarding X-ray radiation. Should replacement be
necessary, replace only with the value originally used.
When replacing components identiÞ ed by
Y
, make the necessary
adjustments as indicated. If the results do not meet the speciÞ ed value,
change the component identiÞ ed by
X
and repeat the adjustment until
the speciÞ ed value is achieved. (See page 10)
When replacing the parts listed in the table below, it is important to
perform the related adjustments.