Sony SAL20F28 - Wide-angle Lens - 20 mm User manual

SERVICE NOTE
SPECIFICATIONS
REPAIR PARTS LIST
DISASSEMBLY ADJUSTMENTS
SERVICE MANUAL
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Link
Revision History
Revision History
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Sony EMCS Co.
SAL20F28 (2.0/28) (20mm F2.8)
Ver 1.2 2007.05
LENS FOR DSLR CAMERA
2007E0800-1
© 2007.05
Published by KohdaTEC9-852-113-12
US Model
Canadian Model
AEP Model
Chinese Model
SAL20F28
(2.0/28) (20mm F2.8)

— 2 —
SAL20F28 (2.0/28) (20mm F2.8)
SPECIFICATIONS
• Depending on the lens mechanism, the focal length may change with any change of the shooting distance. The focal length assumes the lens is focused
at infinity.
Equivalent 35mm-format focal length*1(mm)
30
*1The value for equivalent 3 mm-format focal length is based on Digital Single Lens Reflex Cameras equipped with an APS-C sized image sensor.
Lens groups elements
9-10
Angle of view 1*1
94°
Angle of view 2*1
70°
*2The value of angle of view 1 is based on 3 mm-format cameras, and that of angle of view 2 is based on Digital Single Lens Reflex Cameras
equipped with an APS-C sized image sensor.
Minimum focus (m (feet))*3
0.2 (0.8)
*3Minimum focus is the shortest distance from the image sensor to the subject.
Maximum magnification (××
××
×)
0.13
Minimum f-stop
f/22
Filter diameter (mm)
72
Dimensions (maximum diameter ××
××
×height) (mm (in.))
Approx. 78 × 3. (3 1/16 × 2 1/8)
Mass (g (oz.))
Approx. 28 (10 /16)
Included items
Lens (1), Front lens cap (1), Rear lens cap (1), Lens hood (1), Set of printed documentation
Designs and specifications are subject to change without notice.

—3 —
SAL20F28 (2.0/28) (20mm F2.8)
TABLE OF CONTENTS
Section Title Page
1. SERVICE NOTE
1-1. Chemicals ·······································································1-1
1-2. Exterior Parts··································································1-1
1-3. Unleaded Solder ·····························································1-1
1-4. Safety Check-out ····························································1-2
1-5. Troubleshooting ·····························································1-3
2. DISASSEMBLY
2-1. Disassembly ···································································2-2
3. REPAIR PARTS LIST
3-1. Exploded Views ······························································3-1
3-2. Supplied Accessories······················································3-6
4. ADJUSTMENTS
4-1. Preparations····································································4-1
4-2. Aperture Diameter Check/Adjustment···························4-4
4-3. Projective Resolving Power Check ································4-9
4-4. Flange Back (f’F) Check/Adjustment ··························4-12
4-5. Lens ROM Check·························································4-16
4-6. Error Code List·····························································4-17

SAL20F28 (2.0/28) (20mm F2.8) 1-1
1. SERVICE NOTE
1-1. Chemicals
Some chemicals used for servicing are highly volatile.
Their evaporation caused by improper management affects your health and environment, and wastes resources.
Manage the chemicals carefully as follows.
• Store chemicals sealed in a specific place to prevent from exposure to high temperature or direct sunlight.
• Avoid dividing chemicals into excessive numbers of small containers to reduce natural evaporation.
• Keep containers sealed to avoid natural evaporation when chemicals are not in use.
• Avoid using chemicals as much as possible. When using chemicals, divide only required amount to a small plate from the container and
use up it.
1-2. Exterior Parts
Be careful to the following points for exterior parts used in this unit.
• Use a piece of cleaning paper or cleaning cloth for cleaning exterior parts.Avoid using chemicals.
Even if you have to use chemicals to clean heavy dirt, don’t use paint thinner, ketone, nor alcohol.
• Insert the specific screws vertically to the part when installing a exterior part.
Be careful not to tighten screws too much.
1-3. Unleaded Solder
This unit uses unleaded solder.
Boards requiring use of unleaded solder are printed with the lead free mark (LF) indicating the solder contains no lead.
(Caution: Some printed circuit boards may not come printed with the lead free mark due to their particular size.)
: LEAD FREE MARK
Be careful to the following points to solder or unsolder.
• Set the soldering iron tip temperature to 350 °C approximately.
If cannot control temperature, solder/unsolder at high temperature for a short time.
Caution: The printed pattern (copper foil) may peel away if the heated tip is applied for too long, so be careful!
Unleaded solder is more viscous (sticky, less prone to flow) than ordinary solder so use caution not to let solder bridges
occur such as on IC pins, etc.
• Be sure to control soldering iron tips used for unleaded solder and those for leaded solder so they are managed separately. Mixing
unleaded solder and leaded solder will cause detachment phenomenon.

SAL20F28 (2.0/28) (20mm F2.8) 1-2
1-4. SAFETY CHECK-OUT
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 contact high-wattage resistors.
3. Look for unauthorized replacement parts, particularly transistors, that were installed during a previous repair. Point them out to the
customer and recommend their replacement.
4. Look for parts which, through functioning, show obvious signs of deterioration. Point them out to the customer and recommend their
replacement.
5. Check the B+ voltage to see it is at the values specified.
6. Flexible Circuit Board Repairing
•Keep the temperature of the soldering iron around 270 °C during repairing.
•Do not touch the soldering iron on the same conductor of the circuit board (within 3 times).
•Be careful not to apply force on the conductor when soldering or unsoldering.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY MARK 0OR DOTTED LINEWITH
MARK 0ON THE SCHEMATIC DIAGRAMS AND IN THE PARTS
LIST ARE CRITICAL TO SAFE OPERATION. REPLACE THESE
COMPONENTS WITH SONY PARTS WHOSE PART NUMBERS
APPEAR AS SHOWN IN THIS MANUAL OR IN SUPPLEMENTS
PUBLISHED BY SONY.
ATTENTION AU COMPOSANT AYANT RAPPORT
À LA SÉCURITÉ!
LES COMPOSANTS IDENTIFÉS PAR UNE MARQUE 0SUR LES
DIAGRAMMES SCHÉMATIQUES ET LA LISTE DES PIÈCES SONT
CRITIQUES POUR LA SÉCURITÉ DE FONCTIONNEMENT. NE
REMPLACER CES COMPOSANTS QUE PAR DES PIÈSES SONY
DONT LES NUMÉROS SONT DONNÉS DANS CE MANUEL OU
DANS LES SUPPÉMENTS PUBLIÉS PAR SONY.
CAUTION
Dangerofexplosionifbatteryisincorrectlyreplaced.
Replace only with the same or equivalent type.

SAL20F28 (2.0/28) (20mm F2.8) 1-3
1-5. TROUBLESHOOTING
1-5-1. ApertureTrouble
NG
Check operation of
the preset ring.
Replace the defective part.
Check operation of the
preset ring, and replace
the defective part.
Perform the aperture
diameter adjustment.
(See page 4-7.)
Perform the aperture
diameter check.
(See page 4-4.)
NG
Check operation
of the diaphragm
control block.
OK OK
OK
Function NG F No. NG
Aperture trouble
Replace the defective part.
NG
NGNG
END
OK
Perform the aperture
diameter check.
(See page 4-4.)

SAL20F28 (2.0/28) (20mm F2.8) 1-4
1-5-2. FocusTrouble
Check the operation
again.
Replace the defective part
or apply the grease.
OK
NG
OK
OK
OK
OK
Function NG Position NG
Focus trouble
Replace the defective part
or apply the grease.
Check the coupler.
Check the outer barrel
and focus ring.
NGNG
NG
NG
NG
END
OK
Check the installation of
the main flexible unit.
reinstall the main
flexible unit.
Check pattern
of the main flexible unit.
Clean the pattern of the
main flexible unit.
Replace the
main flexible unit.
Check the foecusing
operation again.

2-1
SAL20F28 (2.0/28) (20mm F2.8)
Cut and remove the part of gilt
which comes off at the point.
(Be careful or some
pieces of gilt may be left inside)
2. DISASSEMBLY
NOTE FOR REPAIR
• Make sure that the flat cable and flexible board are not cracked of bent at the terminal.
Do not insert the cable insufficiently nor crookedly.
• When remove a connector, dont’pull at wire of connector. It is possible that a wire is snapped.
• When installing a connector, dont’press down at wire of connector.
It is possible that a wire is snapped.
• Do not apply excessive load to the gilded flexible board.
UNIVERSALWRENCH
In case of the following notches or holes are located in the lens block, etc during disassembling/
assembling the lens, Use the universal wrench.
How to Use
Attach the chip-A or chip-B to the universal wrench.
For the notches: chip-A
For the holes: chip-B
Match the universal wrench to the holes or notches of the lens block, etc.
Notches Holes
Universal wrench
J-6082-609-A
Chip-A for
universal wrench:
J-6082-609-1
Chip-B for
universal wrench:
J-6082-609-2
Notches
Chip-A
Chip-A
Chip-B
Chip-B
Chip
Chip
Match the universal wrench
to the width of holes or notches. Universal wrench
Holes
Ver 1.1 2007.01

2-2
SAL20F28 (2.0/28) (20mm F2.8)
2-1. DISASSEMBLY
2-1-1. FOCUS RING, FRONT LENS BARREL AND FIXEDTUBE
EXPLODEDVIEW Note:
Remove the decoration ring using the name
ring wrench C (72 mm).
Name ring wrench C (72 mm):
J-6082-634-A
Name ring wrench C (72 mm)
HELP01
HELP13
3Front Lens
Barrel
42nd Lens
Block
X
T
HELP02
5Focus
Ring
HELP03
(See Page 2-3.)
XT
RUZ
Y
Z
R
UY
21st Lens
Block
1Decoration
Ring
6Outer Barrel Hold
Plate
7Outer Barrel
Ver 1.2 2007.05

2-3
SAL20F28 (2.0/28) (20mm F2.8)
2-1-2. REAR LIGHT SHIELD BARREL, LENS MOUNT BLOCK AND OUTSIDE BARREL
1Lens Mount Riveting Block
HELP06
HELP14
EXPLODEDVIEW
3Rear Light Shield Barrel
HELP05
HELP04
HELP09
4Main Flexible Unit
Lens Mount Block
HELP07
HELP08
5Coupler
B
C
A
D
2Main
Spring
(See Page 2-4.)
AB
D
C
6Outside
Barrel
FLANGE BACK
ADJUSTMENT
7Back
Adjustment
Washer