Seiko V181A Quick start guide

PARTS LIST/TECHNICALGUIDE
ANALOGUE SOLAR Cal. V181A
[SPECIFICATIONS]
1/18
Item Cal. No. V181A
Power reserve
Driving system
Additional function
Crown operation
Loss/Gain
Regulation system
Number of jewels
Normal position
1st click position
Current consumption
Gate time for rate measurement
Power supply
Motion of the second hand
Coil resistance
Power
generator
Rechargeable
battery
Operating
voltage range
One-second intervals
Stepping motor 1 piece
Movement
Diameter
Outside: 20.0mm
Casing: 19.4mm
Height: 2.20mm
3 hands (hour, minute and
second hands)
Instart-start function
Energy depletion forewarning function (The second hand moves at
two-second intervals.)
Overcharge prevention function
Electronic circuit reset function
Second hand stop function
Free
Time setting
Monthly rate:less than 20 seconds (worn on the wrist at
temperature range between 5 to 35 degrees Centigrade)
Use 10-second gate
Nil
Solar power generation system
Movement: less than 0.80 μA
Circuit block: less than 0.40 μA
Coil block: 1.80 - 2.20 KΩ
MT616 Manganese titanium lithium rechargeable battery
0.45V - 2.20V
From full charge to stoppage: Approximately 2 months
2 jewels

SPECIFICATIONS
2/18
Cal. V181A
FEATURES
The Cal. V181 is an analogue watch with a solar power generation system.
l Solar power generation system
The watch operates while charging electricity by converting light received on the dial to
electrical energy. It lasts for 2 months after full charge.
l Energy depletion forewarning function
When the energy stored in the rechargeable battery is reduced to an extremely low level, the
second hand starts moving at 2-second intervals instead of the normal 1-second intervals.
l Instant-start function
When the watch is exposed to sunlight or strong artificial light (of more than 1,000 lux), it will
start operating immediately with the second hand moving at 2-second intervals.
l Guideline of charging time
Environment/Light source Illumination
(lux)
Time required
for full charge
Time required
for steady
operation
Time to charge
1 day of power
60W 60cm/Incandescent
light
500 110 hours 8 hours 100 minutes
General offices/ Fluorescent
Light
700 82 hours 6 hours 75 minutes
30W 70cm/Fluorescent light 1,000 60 hours 4 hours 55 minutes
30W 20cm/Fluorescent light 3,000 20 hours 1.3 hours 18 minutes
30W 12cm/Fluorescent light 5,000 10 hours 33 minutes 9 minutes
30W 3cm/ Fluorescent light 10,000 5 hours 15 minutes 5 minutes
Cloudy weather/Sunlight 10,000 5 hours 15 minutes 5 minutes
Fair weather/Sunlight 100,000 2.1 hours 7 minutes 2 minutes
The above table provides only a general guideline.
It is recommended that the watch be charged for as long as the charging time according to the
column "Time required for steady operation" in this table in order to assure the stable movement
of the watch.
l Caution for charging
When charging the watch, do not place it too close to a photo flash light, spotlight, incandescent
light or other light sources as the watch temperature will become extremely high, causing damage
to the parts inside the watch.
When exposing the watch to sunlight to charge it, do not leave it on the dashboard of a car, etc.
for a long time, as the watch temperature becomes extremely high.
While charging the watch, make sure the watch temperature does not exceed 50 °C.

PARTS LIST Cal. V181A
3/18
28
28
SOLAR CELL UNIT
Large: 4025543
Small: 4025575
CONTACTSPRINGFOR
SOL A R C ELL UNIT
4246644
CASING RING
Large: 82840960
Small: 82840940
EARTHING SPRING
4281503
DIAL WASHER
0491735
HOUR WHEEL
0271500
[SOLAR POWER GENERATION MECHANISM]
Order of disassembly:
Order of assembly:
1
1
1
2
3
4
5
6
Lubricating : Types of lubricant
Watch Oil AO-3
Watch Oil AO-2
Lubricant quantity:
Normal quantity

Cal. V181A
PARTS LIST
4/18
SETTING STEM
0351500
MAIN PLATE
0100978
RECHARGEABLE
BATTERY UNIT
302729Y
CIRCUIT BLOCK
COVER SCREW
0022247
CIRCUIT BLOCK
COVER
4457923
CIRCUIT BLOCK
4000656
TR AIN WHEEL
BRIDGE
0125907
FOURTH WHEEL
0241929
THIRD WHEEL
0231904
FIFTH WHEEL
0701904
STEPPING ROTOR
4146907
MINUTE WHEEL
0261907 SETTING WHEEL
0281904
TR AIN WHEEL
SETTING LEVER
0391890
COIL BLOCK
4002907
ROTOR STATOR
4239908 SETTING LEVER
0383176
YOKE
0384890
CLUTCH WHEEL
0282890
CENTER WHEEL
0221929 BATTERY
CONNECTION(+)
4268656
RECHARGEABLE
BATTERY UNIT SCREW
0022247
26
27
24
Please see the remarks on the following pages.
7
8
9
10
11
12
13
14
15
18
19
16
17
28
[BATTERY AND ELECTRONIC CIRCUIT
- GEAR TRAIN MECHANISM AND STEPPING MOTOR -
SETTING MECHANISM]
20
21
22
23
25

PARTS LIST Cal. V181A
5/18
l How to find the correct parts, if not determined by 4 digit caliber number
Following parts are determined based on the design of watches, such as hands height, dial color,
and design of cases. Please refer to the SEIKO WATCH PARTS CATALOGUE in order to choose
corresponding parts.
Casing ring Large: 82840960 Small: 82840940
Setting stem 0351500
*
For screw down crown models, the stem is assembled to the crown and is not available
separately.
Note:
Solar cell unit Large: 4025543 Small: 4025575
* When ordering this part, make sure which size you need by visually observing the disassembled
part. Our parts catalogue currently shows both sizes under the same model .
4
1
24

Cal. V181A
PARTS LIST
6/18
lTools and consumables required for disassembling/reassembling
•Movement holder
UNIVERSAL MOVEMENT HOLDER (S-682)
• Watch oils
SEIKO watch oils (AO-3 and AO-2)
AO-3 AO-2

TECHNICAL GUIDE Cal. V181A
7/18
Crown position: normal position
Push the SETTING LEVER gently (refer to the Fig. 1) in order
to disengage it from the SETTING STEM. Then pull out the
crown with the stem completely.
REMARKS ON DISASSEMBLING AND REASSEMBLING THE MOVEMENT
lHOW TO REMOVE THE SETTING STEM BEFORE DISMANTLING THE MOVEMENT
lSOLAR POWER GENERATION MECHANISM – POSITIONS OF THE HOOKS
A
ab
B
c
HOOK
SCREWDRIVER
SOLAR CELL UNIT
DIAL
<Disassembling>
Dial
The dial is fixed to the CASING RING with four hooks of the
CASING RING (a, b, c and d in Fig. 2).
When disassembling the dial, insert the tip of a screwdriver
into a gap between the dial and the SOLAR CELL UNIT near
a hook, then, ply up the dial to release it (refer to the Fig.
3) . Follow the same procedure to release all the four
hooks.
Note: Please be careful not to scratch the SOLAR CELL UNIT
under the dial when disassembling the dial from the CASING
RING.
Fig. 1
Fig. 2
Fig. 3

TECHNICAL GUIDE Cal. V181A
8/18
When disassembling the SOLAR CELL UNIT, insert the
tip of a screwdriver into a gap between the SOLAR CELL
UNIT and the CASING RING near a hook of the CASING
RING, then, ply up the SOLAR CELL UNIT to release it
(refer to the Fig. 6). Follow the same to release all the
hooks except for the hook c for the small size SOLAR CELL
UNIT.
When releasing the hook c for the small size SOLAR CELL
UNIT, release the hook a and b, then, gently slide the SOLAR
CELL UNIT as illustrated in Fig. 7. DO NOT insert a
screwdriver near the hook c as it may damage the SOLAR
CELL UNIT.
HOOK
SCREWDRIVER
SOLAR CELL UNIT
CASING RING
ab
c
d
a
c
b
c
SOLAR CELL UNIT
Fig. 5 (Small size)
Fig. 6
Fig. 7
Fig. 4 (Large size)
(1) SOLAR CELL UNIT
The positions of a hook for the SOLAR CELL UNIT are different for a large size one (a, b, c and d in Fig.
4) and a small size one (a, b and c in Fig. 5). Following illustrations show their positions for each size of
the SOLAR CELL UNIT.
1

TECHNICAL GUIDE Cal. V181A
9/18
(3) EARTHING SPRING
The EARTHING SPRING is fixed to the CASING RING with
its two hooks (a and b in Fig. 8). Please release them when
disassembling the spring from the CASING RING.
(4) CASING RING
When disassembling the CASING RING from the movement,
release its two hooks (a and b in Fig. 9).
<Reassembling>
When reassembling the CASING RING, the EARTHING SPRING, the SOLAR CELL UNIT and the dial,
please make sure that all the hooks are secured.
lRECHARGEABLE BATTERY AND ELECTRONIC CIRCUIT
(8) RECHARGEABLE BATTERY UNIT
(1) CIRCUIT BLOCK COVER
The cover has three hooks to fix it to the MAIN PLATE (Fig.
11). Make sure that all the hooks are disengaged or secured
when disassembling or reassembling it.
Please refer to the ass emb ly p osition of the
RECHARGEABLE BATTERY UNIT as illustrated in Fig.
10.
a
b
Fig. 8
Fig. 9
Fig. 10
Fig. 11
MOVEMENT
CASING RING
a
b
RECHARGEABLE
BATTERY UNIT
3
4
8
10
8
4

TECHNICAL GUIDE Cal. V181A
10/18
l GEAR TRAIN MECHANISM - WHEEL ASSEMBLY POSITION AND LUBRICATION
INSTRUCTIONS
13) FOURTH WHEEL 16) STEPPING ROTOR
14) THIRD WHEEL 17) MINUTE WHEEL
FIFTH WHEEL 18) SETTING WHEEL
FIFTH WHEEL
THIRD WHEEL
FOURTH WHEEL
MINUTE WHEEL
SETTING WHEEL
CENTER WHEEL
FOURTH WHEEL
MINUTE WHEEL
FIFTH WHEEL THIRD WHEEL
SETTING WHEEL
STEPPING ROTOR
STEPPING ROTOR
Fig. 12 Wheel assembly position Fig. 13 Lubrication instructions
l SETTING MECHANISM - ASSEMBLY POSITION AND LUBRICATION INSTRUCTIONS
TRAIN WHEEL SETTING LEVER (Fig. 16)
SETTING LEVER (Fig. 15)
YOKE (Fig. 14)
YOKE SETTING LEVER
TRAIN WHEEL
SETTING LEVER
CLUTCH WHEEL
25
16
17
13
14
15 18
16 17
13
14
15 18
26
16
13
17
15
18
14
Fig. 14 Fig. 15 Fig. 16
19
22
23 22
19
23

TECHNICAL GUIDE Cal. V181A
11/18
l CHECKING THE ELECTRICAL CHARACTERISTICS
<Coil resistance>
Check the resistance of the COIL BLOCK if it falls between 1.80 and 2.20 kΩ.
<How to measure the current consumption for the whole movement>
1)
Remove the SOLAR CELL UNIT and the RECHARGEABLE BATTERY UNIT from the
movement.
2) Connect the (-) probe to the (-) input terminal of the
CIRCUIT BLOCK and (+) probe to the BATTERY
CONNECTION (+) as illustrated in Fig. 17.
* When measuring the current consumption using
the SEIKO digital multi-tester (S-860), use the
range of 40μA of SUPPLY V (=1.55V) & GATE
TIME (2S).
3) Wait until a stable measurement becomes available. It usually takes 30 seconds to a few minutes
for getting a stable measurement.
4) Make sure that the read value is less than 0.80μA.
REMARKS ON INSPECTION AND MEASUREMENT
Fig. 18
1
20
8
11
27
27
(-) INPUT
TERMINAL
BATTERY
CONNECTION (+)
Fig. 17

TECHNICAL GUIDE Cal. V181A
12/18
(+) INPUT TERMINAL
(-) INPUT TERMINAL
CRYSTAL
OSCILLATOR
UNIT
SOLAR CELL
UNIT
(+) INPUT TERMINAL
SOLAR CELL
UNIT
(-) INPUT TERMINAL
C-MOS-IC
COIL OUTPUT
TERMINAL
* When measuring the current consumption using
the SEIKO digital multi-tester (S-860), use the
range of 40μA of SUPPLY V (=1.55V) & GATE
TIME (2S).
* AvoidexposingtheCIRCUITBLOCKtodirect light
in order to obtain the correct measurement.
2) Wait until a stable measurement becomes available. It usually takes 30 seconds to a few minutes
for getting a stable measurement.
3) Make sure that the read value is less than 0.40μA.
Note: In case the measurement of the current consumption for a whole movement exceeds the standard
value but the measurement for the circuit falls below the standard value, a problem in the gear train
mechanism is suspected. Please disassemble and overhaul the movement and measure the current
again.
Fig. 20
<How to measure the current consumption for the CIRCUIT BLOCK alone>
1) Connect each probe to the appropriate (-) and (+) input terminal of the CIRCUIT BLOCK (please
refer to the "Structure of the CIRCUIT BLOCK" below).
[Structure of the CIRCUIT BLOCK]
Fig. 19
11

TECHNICAL GUIDE Cal. V181A
13/18
FLUORESCENT LAMP
15 - 20 W
l CHECKING THE SOLAR POWER GENERATION SYSTEM
8
10
<How to check the solar power generation with the watch>
1) Remove the RECHARGEABLE BATTERY UNIT from
the watch.
2) Pull out the crown to the 1st click in order to reset the
circuit.
3) Connect the (-) probe to the (-) input terminal for the
SOLAR CELL UNIT and (+) probe to the CIRCUIT
BLOCK COVER (as illustrated in Fig.21).
* When measuring the voltage using the SEIKO digital
multi-tester (S-860), use the range of mV (Fig. 22).
4) Expose the watch to the light of a fluorescent lamp
(use the one with 15 to 20 watts) at a distance of 5 cm
while connecting the probes to the watch (Fig. 23).
5) Read the measurement and check if it exceeds 2.3 V.
5 cm
Fig. 22
Fig. 23
Fig. 21

TECHNICAL GUIDE Cal. V181A
14/18
Note: In case the measurement of the voltage for the watch does not achieve the standard value but
the measurement for the solar cell unit alone exceeds the standard value, a problem in the electrical
conductivity between the solar cell unit and the movement is suspected. Inspect the electrical conductivity,
especially at the CONTACT SPRING FOR SOLAR CELL UNIT, and check the solar power generation
system again.
2
<How to check the solar power generation with the SOLAR CELL UNIT alone>
1) Connect each probe to the appropriate (-) and (+) output terminal of the SOLAR CELL UNIT. As
the positions of the output terminal are different for a large size one and a small size one, please
refer to the following illustrations in order to find the right positions of the terminal.
* When measuring the voltage using the SEIKO digital
multi-tester (S-860), use the range of mV (Fig. 26).
2) Expose the SOLAR CELL UNIT to the light of a
fluorescent lamp (use the one with 15 to 20 watts) at
a distance of 5 cm while connecting the probes to the
solar cell unit (Fig. 27).
3) Read the measurement and check if it exceeds 2.3 V.
Fig. 26
5 cm
Fig. 27
Fig. 24 ( Large size ) Fig. 25 ( Large size )
FLUORESCENT LAMP
15 - 20 W
1

TECHNICAL GUIDE Cal. V181A
15/18
l CHECKING THE INSTANT-START FUNCTION
The instant-start function works when the voltage of the rechargeable battery is more than 0.9V.
Therefore, please measure the battery voltage and make sure that the battery is ready for checking the
instant-start function.
* When measuring the voltage of the rechargeable
battery, connect the (-) probe to the RECHARGEABLE
BATTERYUNIT SCREWand (+) probe to the CIRCUIT
BLOCK COVER as illustrated in Fig. 28.
<How to check the instant-start function>
1) Place the watch which stops working at a distance of
50 cm under the fluorescent lamp of 15 to 20 watts
(Fig. 29).
2) Check if the second hand of the watch starts moving
at 2-second intervals within 10 seconds.
FLUORESCENT LAMP
15 - 20 W
50 cm
Fig. 29
Fig. 28
7
10

TECHNICAL GUIDE Cal. V181A
16/18
l CHECKING THE RECHARGING FUNCTION
In order to check the recharging function, measure the voltage of the rechargeable battery before and
after recharging. If the voltage increases to a certain extent, it shows that the recharging function is
working properly.
1) Measure the voltage of the rechargeable battery before recharging (please refer to Fig. 28 of
page 15 for where to apply the probes of the tester).
2) Recharge the watch by placing it at a distance of 5 cm under the fluorescent lamp of 15 to 20
watts for 30 minutes (Fig. 30).
FLUORESCENT LAMP
15 - 20 W
5 cm 5 cm
FLUORESCENT LAMP
15 - 20 W
Fig. 31
Fig. 30
3) Measure the voltage again while keeping the watch exposed to the light (Fig. 31).
4) Compare the difference of the voltage before and after recharging. Refer to the table
below for the criteria of the inspection.
0.50V - 1.00V
Results after recharging and criteria for checking the function
Recharging function works fine
The voltage
BEFORE recharging
1.01V - 1.30V
Less than 1.19V
Increased by 0.04V or more
More than 1.20V
Not increased or increased
but not more than by 0.04V
The battery needs to be inspected and
replaced if necessary
Table - criteria recharging function Cal. V181A

TECHNICAL GUIDE Cal. V181A
17/18
l CHECKING THE GENERAL FUNCTION
Operation Function Checkpoint
Pull out the crown
to the 1st click
and push it back
in to the normal
position. Repeat
the same several
times.
Setting mechanism -
switching the
function of the time
setting
Make sure that it has
a click at each
position and the stem
is not pulled off.
Pull out the crown
to the 1st click,
then turn it.
Second hand stop
function (if available)
Make sure that the
second hand stops
when the crown is
pulled out to the 1st
click.
Setting mechanism -
hour and minute
hand setting
Make sure that the
hour and minute
hands move
smoothly (without
touching each other
or touching the
surface of the dial or
inside of the glass).
Hands installation

TECHNICAL GUIDE Cal. V181A
18/18
l CHECKING THE WATER RESISTANCE
l CHECKING THE ACCURACY - INSTANTANEOUS RATE
Measure the rate and make sure the value shows within ±0.66 s/d.
Use 10-second gate of the tester.
Marking on the case back Test method Applied pressure
WATER RESISTANT (WATER RESIST) 3 BAR
WATER RESIST 5BAR 5 BAR
WATER RESIST 10BAR 10 BAR
WATER RESIST 15BAR 15 BAR
WATER RESIST 20BAR 20 BAR
SCUBA DIVER'S (AIR DIVER'S) 150 m 18.75 BAR = 150 (m) times 0.125
SCUBA DIVER'S (AIR DIVER'S) 200 m 25 BAR = 200 (m) times 0.125
He-GAS DIVER'S 300 m 37.5 BAR = 300 (m) times 0.125
He-GAS DIVER'S 600 m 75 BAR = 600 (m) times 0.125
He-GAS DIVER'S 1000 m 125 BAR = 1000 (m) times 0.125
Water pressure test
Condensation test
Condensation test
Condensation test
Water pressure test
Air leak test
Check the water resistance according to the designated specification of the watch.
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