Sony HMD-A420 Service Manual ▷ View online
HMD-A420
Part Replaced (
] )
D board
IC502, R515, T501 (FBT)
•
Mounted D Board
D board
D538, IC901, Q534, R521,
R551, R552, R598, R599,
T501 (FBT)
R551, R552, R598, R599,
T501 (FBT)
•
Mounted D Board
D board
IC901, R911, R949, R950,
T501 (FBT)
T501 (FBT)
•
Mounted D Board
RV501
SECTION 3
SAFETY RELATED ADJUSTMENT
3-1
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.
Allow the unit to warm up for one minute prior to checking
the following conditions:
a) HV Regulator Check
1)
Input white cross hatch signal. (fH = 69 kHz)
2)
CONT maximum and BRT center
3)
Cut off Screen VR (G2).
4)
Input voltage: 120 ± 2 VAC
5)
Confirm that the voltage is within the voltage range
shown below.
Standard voltage: 26.9 KV ± 0.4 KV
6)
When replacing components identified by
], make sure
to recheck the High Voltage.
7)
Verify the High Voltage as shown above (26.9 KV ± 0.4
KV) is within specification. If not, set H. SIZE data at
minimum (-127) and then adjust RV501 on "D" Board.
8)
After adjusting the High Voltage within specification,
put the RV cover on RV501 as shown below and apply
sufficient amount of RTV around RV501.
b) HV Protector Circuit Check
1)
Confirm that the voltage between cathode of D517 an
GND is more than 27.5 VDC.
2)
Using an external DC Power supply, apply the voltage
shown below between cathode of D517 on "D" and
GND, and confirm that the HV Hold-Down circuit
works. (Raster disappears) Apply DC Voltage: Less than
35.8 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
c) Beam Protector Check (Software logic)
1)
Using an external current source, apply < 1.55mA
between pin qa of FBT (T501) and GND, and confirm
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)
d) B+ Voltage Check
1)
Input white cross hatch (fH = 69 kHz) signal.
2)
CONT (max) & BRT (center)
3)
Input voltage: 120 ± 2 VAC
Note: Use NF power supply or make sure that distortion
factor is 3% or less.
4)
Confirm that the voltage is within the voltage range
shown below.
Standard voltage: 179 ± 3.0 VDC
HV Regulator
Circuit
Circuit
HV HOLD
DOWN Circuit
DOWN Circuit
Beam Current
Protector Circuit
Protector Circuit
HMD-A420
*The parts above ( ~ ) are necessary for DAS adjustment.
IBM AT Computer
as a Jig
1-690-391-21
1
A-1500-819-A
Interface Unit
Interface Unit
2
3
D-sub
(9 Pin [female])
(9 Pin [female])
mini Din
(8Pin)
(8Pin)
4 Pin
3-702-691-01
Connector Attachment
Connector Attachment
3
To BUS CONNECTOR
4 Pin
4 Pin
1
CRT
Neck Ass’y
A Board
Purity
Magnet
XCV VR
6-pole
Mg
TLH Plate
DY
4-pole
Mg
H-Trp VR
TLV VR
YCV VR
SECTION 4
ADJUSTMENTS
4-1
Connect the communication cable of the connector located on the D board on the monitor. Run the service software and then follow
the instructions.
Allow a 30 minute warm-up period prior to making the following adjustments:
4-1. Landing Rough Adjustment
1.
Display the all white pattern.
2.
Adjust the contrast to maximum value.
3.
Display the 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.
Moving the DY forward, adjust so that an entire
screen becomes pure green.
6.
Adjust the tilt of DY and tighten lightly with a clamp.
4-2. 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 hand-degausser.
5.
Perform auto degauss.
6.
Attach a wobbling coil to the specified 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].
1.
Display crosshatch pattern with green lines and black
field.
2.
Adjust V. Key (=H. Trapezoid) with H-Trp VR so that
[a] is equal to [b].
3.
Change “CONV_OFF_NDX” to “7”.
12. If the corner landing is out of specification, use a disk
magnet for the landing correction.
13. If disk magnets were used, perform an auto degauss.
14. Remove the wobbling coil and sensor.
15. Fix the purity magnet on DY with white paint.
4-3. 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.
4-4. Convergence and V. Key (H. Trp) Fine Adjustment
HMD-A420
4-2
4.
Display crosshatch pattern with red and blue lines and
black field.
5.
Adjust H.STAT and V.STAT with 4 pole magnet. Use
4 pole magnet, not “HSTAT” and “VSTAT”.
6.
Display crosshatch pattern with white lines and black
field.
7.
Adjust HMC and VMC with 6 pole magnet.
8.
Display crosshatch pattern with red and blue lines and
black field.
9.
If necessary, repeat steps 5-8.
10. Change “CONV_OFF_NDX” to “3”.
11. Adjust H.TILT with TLH plate.
12. Adjust XCV with XCV VR.
13. Adjust YCH with YCH VR.
14. Adjust V.TILT with TLV VR.
15. If necessary, repeat steps 3-14 to make the optimum
condition for the entire screen.
16. Fix 4-pole magnet, 6-pole magnet and XCV VR with
white paint.
4-5. Vertical and Horizontal Position and Size
Specification
4-6. Focus adjustment
Adjust focus (V) and focus (H) for optimum focus.
4 Pole Magnet
6 Pole Magnet
TLH movement
R B
B R
XCV movement
YCH movement
R
B
TLV movement
Zero Position NECK Ass'y
a < 3.0 mm
b < 3.0 mm
b < 3.0 mm
A B
234 312
b
b
a
a
A
B
Focus (V)
Focus (H)
FBT
5-1
5-2
SECTION 5
DIAGRAMS
5-1. BLOCK DIAGRAMS
SIGNAL-IN
HD15
PIG-TAIL
TO D BOARD
CN901
CN901
TO D BOARD
CN902
CN902
B
A
TO D BOARD
CN603
CN603
C
TO
D BOARD
FBT
D BOARD
FBT
HV
G2
FV1
CRT
R.G.B
G1
2
IC001 PRE AMP,OSD MIX
6
32
11
19
15
26
4
6
7
5
9
13
1
13
15
17
12
10
21
20
6
5
27
25
24
23
CLAMP AMP
Q001,002
1
5
11
15
6
10
4
14
9
3
13
8
2
12
7
35
29
8
9
IC002
RGB OUT
11
5
3
1
F
TO D BOARD
CN502
CN502
E
TO D BOARD
CN504
CN504
IC003 OSD
IC004 AMP
P7
P1/R
R OUT
R IN
R VOUT2
R VIN2
G VOUT3
G VIN3
B VOUT1
B VIN1
G OUT
G IN
B OUT
B IN
DA4
DA3
DA2
DA1
OSDR
OSDG
OSDB
OSD BLKIN
SDA
SCL
CLAMP
ABL IN
BLK
P3/G
P5/B
P0/BK0
SIN
SCK
19
18
VERT
HOR
(VIDEO, RGB OUT)
A
TO
D BOARD
FBT
D BOARD
FBT
FV2
TO
D BOARD
FBT
D BOARD
FBT
B-SS3545<AEP>-BD1-EPS05
P701
MENU
ORANGE/LED
GREEN/LED
1
2
3
D
TO D BOARD
CN903
CN903
(USER CONTROL)
H
SW701
LED701
POWER
MENU
B CUT-OFF
Q301
G CUT-OFF
Q201
R CUT-OFF
Q101
G2 CONT
Q004
H SYNC
BUFF
Q003
V SYNC
BUFF
Q005
2
1
4
3
3
CN304
CS0
CS1
CS2
CS3
9
P6
16
P4
14
P2
–
+
+81V
+12V
+6.3V
+5V
D105
D205
D305
CN301
5
7
1
2
9
RED
GREEN
H-IN
V-IN
BLUE
CN306
4
3
2
2
PC DET
DDC SDA
DDC SCL
CN305
6
5
3
1
4
DDC SCL
DDC SDA
V-IN
H-IN
PCDET
CN302
7
3
4
8
9
5
CLAMP
H_RTN
V_RTN
SDA/I
SCL/I
G1
5
1
3
4
6
CN303
ABL
+81V
+12V
+6.3V
+5V
5
1
3
4
6
ABL
+81V
+12V
+6.3V
+5V
1
CN309
1.2kV
IC009
ROM
VCLK
SDA
SCL
7
5
6
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