Seiko A860A Installer manual

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PARTS CATALOGUE/TECHNICALGUIDE
Cal. A860A
Cal. A861A
[SPECIFICATIONS]
Cal. No.
Item A860A A861A
(x 1.0)The illustrations refer to Cal. A860A.
Module
Module size Outside diameter ø32.0 mm
31.6 mm between 3 o’clock and 9 o’clock sides
31.7 mm between 6 o’clock and 12 o’clock sides
–Casing diameter
Height 7.1 mm (Including the battery portion)
Display medium Nematic Liquid Crystal, FEM (Field Effect Mode)
Liquid crystal driving system Multiplex driving system
Display system • Time display
• Stopwatch display (In 1/100 second increments for the first 20 minutes)
• Alarm display
Additional mechanism • Speaking function (Current time, stopwatch measurements, hourly
time signal, alarm time and selected digits to be adjusted)
• Battery life indicator
• Alarm test system
Loss/gain Monthly rate at normal temperature range: less than 20 seconds
Regulation system Nil
Measuring gate by quartz tester Any gate can be used.
Battery SEIKO CR2025, Maxell CR2025, Sony CR2025, Matsushita CR2025,
Eveready ECR2025
Battery life is approximately 2 years.
Voltage: 3.0 V

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PARTS CATALOGUE Cal. A860A, A861A
Disassembling procedures Figs. : 1 →21
Reassembling procedures Figs. : 21 ←1
Lubricating: Types of oil Oil quantity
Silicone oil 500,000 Normal quantity
➡➡Please see the remarks on the following pages.
1 Case back screw
2 Case back
3 Case back gasket
4 Module
5 Spacer screw
6 Spacer
7 4580 009
Speaker block
8 Conductive plate for the side button
9 Conductive plate for the front button
Button B
Button A
Button C
Button spring clip
Button D
(Front button)

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PARTS CATALOGUE Cal. A860A, A861A
110 151
Installing direction
indication sheet
➡➡Please see the remarks on the following pages.
(Reversed battery guard)
(Reversed liquid crystal panel frame)
10 4225 435
Battery clamp
11 Battery
(See the front page.)
12 4245 280
Switch spring (A)
13 4408 068
Washer for switch spring (B)
14 4245 270
Switch spring (B)
15 4395 038
Battery guard
16 4270 371
Battery connection (-)
17 4003 190
Circuit block
18 4313 117
Connector
19 4246 087
Speaker lead
terminal
21 4512 033
Liquid crystal
panel frame
20 4510 355
Liquid crystal
panel

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TECHNICAL GUIDE Cal. A860A, A861A
•The explanation here is only for the particular points of Cal. A860A and A861A.
•For the repairing, checking and measuring procedures, refer to the “TECHNICAL GUIDE, GENERAL
INSTRUCTIONS”.
I. STRUCTURE OF THE CIRCUIT BLOCK
Input terminal (+)
Crystal unit
Input terminal (–)
C-MOS-IC
II. REMARKS ON INSTALLING THE BATTERY
After the battery is replaced with a new one, or after the battery is re-installed following the repairing
procedures, be sure to follow either of the two methods below to reset the circuit.
•METHOD 1
To reset the circuit of a module:
Short-circuit the AC terminal of the circuit block and the
battery positive surface with conductive tweezers as
illustrated at right.
* When the circuit is reset , “AM 12:00 oo” is displayed as the seconds start counting immediately.
* After resetting the circuit, set the time. (See “HOW TO USE”.)
AC terminal
Tweezers
Battery (+) side
•METHOD 2
To reset the circuit of a complete watch:
Press and hold buttons “A”, “B”, “C” and “D” at the same
time for 2 to 3 seconds.
* The display will become blank, indicating that the circuit
is reset.
Button CButton B
Button D
Button A

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TECHNICAL GUIDE Cal. A860A, A861A
Speaker lead
terminal
III. REMARKS ON DISASSEMBLING AND REASSEMBLING
Use the universal movement holder for disassembling and reassembling.
•How to install
Setthespeakerblocksothatthespeakerleadterminal
is positioned between the guide grooves of the case
as shown in the illustration at right.
Note: When installing the speaker block, take care not
to damage its transparent sound diaphram.
Guide groove
8 Conductive plate for the side button
9 Conductive plate for the front button
7 Speaker block
•How to install
• Insert the conductive plates for the side and front buttons into the gap between the button spring
clip and the case middle as shown in the illustrations below.
Conductive plate Case middle
Button spring clip
Conductive plate for the side button Conductive plate for the front button
Case back
Conductive plate
• When closing the case back, check that the
conductive plates are in contact with the case back,
being bent by it towards the center of the watch.
• In doing so, the case back may be hard to set in
position, as the conductive plates have a repelling
force when bent.
10 Battery clamp
•How to remove
Insert the tip of tweezers into the center of the hooking
portion of the battery clamp and pry it up toward the
direction of the arrow in the illustration at right to
remove it.
Tweezers
Battery clamp