Seiko V172A Quick start guide

PARTS LIST /TECHNICAL GUIDE
ANALOGUE SOLAR Cal. V172A/V174A
[SPECIFICATIONS]
1/24
Item Cal. No. V172A/V174A
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
2nd click position
One-second intervals
Stepping motor 4 pieces
Diameter: Outside 27.6 mm
Casing 27.0 mm
Height: 4.4 mm
3 hands
(hour, minute and small
second hands)
Energy depletion forewarning function (The second hand moves at two-
second intervals.)
Overcharge prevention function
Electronic circuit reset function
Second hand stop function
Date calendar
Instant setting device for date calendar
System reset function
Stopwatch function..........60-minute stopwatch in 1/5-second increments
(Auto stop measuring at 60 minutes)
Accumulated elapsed time measurement
Split time measurement
Single-time alarm function
Stopwatch hand position adjustment
Stopwatch
Time setting, System reset, Setting “0” of stopwatch hand
Monthly rate:less than 15 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
4002 541 1.90 - 2.30 kΩ
(COIL BLOCK) (COIL BLOCK FOR STOPWATCH SECOND)
4002 542 1.75 - 2.15 kΩ
(COIL BLOCK FOR STOPWATCH MINUTE) (COIL BLOCK FOR ALARM)
MT920 Manganese titanium lithium rechargeable battery
0.90V - 2.10V
From full charge to stoppage: Approximately 6 months
Nil
V172A V174A
Date setting(counter clockwise), Time setting of alarm
3 hands
(hour, minute and small second
hands), 24-hour indicator

SPECIFICATIONS
2/24
Cal. V172A/V174A
FEATURES
The Cal. V172A/V174A are analogue chronograph watches 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 6 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 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
General offices/ Fluorescent
Light
700 -60 hours 150 minutes
30W 20cm/Fluorescent light 3,000 110 hours 13 hours 33 minutes
30W 3cm/ Fluorescent light 10,000 30 hours 3.5 hours 9 minutes
Cloudy weather/Sunlight 10,000 30 hours 3.5 hours 8 minutes
Fair weather/Sunlight 100,000 5 hours 0.6 hours 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 60 °C.

Order of disassembly: 1
Order of assembly: 1
Lubricating:
Types of oil Oil quantity
AO-3 Normal quantity
1 HOUR, MINUTE
AND SMALL
SECOND HANDS,
24-HOUR HAND
(V174A )
2 DIAL
CASE BACK
3 SPACER FOR
SOLAR CELL
4453 500
4 SOLAR CELL
4025 556(CAL.V172A)
4025 557(CAL .V174 A)
5 HOLDING RING FOR DIAL
0866 ***
6 CONTACT POINT SPRING
2PCS.
4281 516
AO-2
PIEZOELECTRIC ELEMENT 4589 801
CASE BACK GASKET
MOVEMENT
CASE
CROWN
69
69
PARTS LIST Cal. V172A/V174A
3/24

19 THIRD INTERMEDIATE WHEEL
FOR CALENDAR CORRECTION
0962 504
17 GUIDE PLATE FIXING PIN FOR
24-HOUR WHEEL (V174A)
0027 973
10 DATE DRIVING WHEEL
0802 582
7 DATE DIAL GUARD
S C R E W（ 2 P C S . ）
0012 354
8 DATE DIAL GUARD
0808 525
9 DATE DIAL
0878 ***
12 GUIDE PLATE FOR DATE DIAL
0712 507
14 CALENDAR CORRECTOR
SETTING WHEEL
0737 505
18 GUIED PLATE FOR 24-HOUR
WHEEL (V174A)
4488 500
20 SECOND INTERMEDIATE
WHEEL FOR CALENDAR
CORRECTION
0962 504
21 FIRST INTERMEDIATE
WHEEL FOR CALENDAR
CORRECTION
0962 580
11 GUIDE PLATE FOR DATE
DIAL SCREW
0012 354
13 ALARM HOUR WHEEL
0271 645
15 24-HOUR WHEEL (V174A)
1002 534
22 HOUR WHEEL
0271 636
16 INTERMEDIATE 24-HOUR
WHEEL ( V174A)
0817 536
Cal. V172A/V174A
PARTS LIST
4/24

23 RECHARGEABLE BATTERY
GUARD SCREW（3PCS.）
0022 230
29 SECOND HOLD SPRING
0396 580
31 BUZZER LEAD TERMINAL
4246 527
24 RECHARGEABLE BATTERY
G U A R D
4225 616（V172A）
42 25 6 4 4（V174A）
25 RECHARGEABLE BATTERY
BLOCK
3023 24H
26 CIRCUIT BLOCK COVER
S C R E W（ 3 P C S . ）
0022 459
27 CIRCUIT BLOCK COVER
4461 532
28 CONDUCTING PLATE
4224 518
30 CIRCUIT BLOCK
4000 750
PARTS LIST Cal. V172A/V174A
5/24

45 CENTER WHEEL FOR
ALARM
0902 502
42 MINUTE COUNTING WHEEL
0902 500
41 INTERMEDIATE MINUTE
COUNTING WHEEL
0950 590
39 FIRST INTERMEDIATE
SESOND COUNTING WHEEL
0885 590
32 PIN FOR TRAIN WHEEL
BRIDGE
0027 974
33 TRAIN WHEEL BRIDGE
0125 516
34 1/5-SECOND COUNTING
WHEEL
0888 501
36 FORTH WHEEL AND PINION
0241 583
37 THIRD WHEEL AND PINION
0231 580
40 SECOND INTERMEDIATE
1/5-SECOND COUNTING
WHEEL
0885 591
43 MINUTE WHEEL
0261 582
46 ALRAM MINUTE WHEEL
0261 582
35 SMALL SECOND WHEEL
0240 511
44 INTERMEDIATE ALARM
WHEEL
0950 590
38 FIFTH WHEEL AND PINION
0701 581
Cal. V172A/V174A
PARTS LIST
6/24

54 CHRONOGRAPH ROTOR
FOR 1/5-SECOND
4146 710
50 COIL BLOCK FOR
CHRONOGRAPH
MINUTE 4002 542
48 COIL BLOCK
4002 541
49 COIL BLOCK FOR
CHRONOGRAPH 1/5-SECOND
4002 541
53 R O TO R
4146 710
55 CHRONOGRAPH ROTOR
FOR MINUTE 4146 710
58 SETTING WHEEL
0281 580
60 CLUTCH WHEEL
0282 585
62 CENTER WHEEL SPRING
4283 581
65 STATOR
4239 710
66 STATOR FOR
CHRONOGRAPH
1/5 -SECOND
4239 717
67 STATOR FOR CHRONOGRAPH
MINUTE 4239 713
47 COIL BLOCK FOR ALARM
4002 542
52 ALARM ROTOR
4146 710
51 SWITCH LEVER A
4450 703
56 SETTING LEVER
0383 592
57 YOKE
0384 583
59 SETTING STEM
0351 586
61 TRAIN WHEEL SETTING
LEVER
0391 591
63 CENTER WHEEL AND
PINION
0221 604
64 STATOR FOR ALARM
4239 712
68 SWITCH LEVER B
4450 701
69 MAIN PLATE
0100 579
PARTS LIST Cal. V172A/V174A
7/24

59
⑰GUIDE PLATE FIXING PIN 0027 973
㉜TRAIN WHEEL BRIDGE FIXING PIN 0027 974
Refer to the following figures.
④SOLAR CELL 4025 556 (V172A)/4025 557 (V174A)
⑰GUIDE PLATEFIXING PIN
FOR 24-HOUR WHEEL
0027 973
㉜TRAIN WHEEL BRIDGE
FIXING PIN
0027 974
4025 556 (V172A) 4025 557 (V174A)
Cal. V172A/V174A
PARTS LIST
8/24
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
the corresponding parts.
 ⑤HOLDING RING FOR DIAL 0866 ***
 ⑨DATE DIAL 0878 ***
SETTING STEM 0351 586
The type of HOLDING RING FOR DIAL is determined based on the design of cases.
Check the case number and refer to the "SEIKO WATCH PARTS CATALOGUE" to choose the
corresponding parts.

PARTS LIST Cal. V172A/V174A
9/24
lTools and consumables required for disassembling/reassembling
•Movement holder
UNIVERSAL MOVEMENT HOLDER (S-682)
• Watch oils
SEIKO watch oils (AO-3 and AO-2) and SEIKO watch grease S-6
AO-3 AO-2
S-6

TECHNICAL GUIDE Cal. V172A/V174A
10/25
REMARKS ON DISASSEMBLING AND REASSEMBLING
Set the notched portions of the dial to the guide posts (4 posts)
of the HOLDING RING FOR DIAL, and check that the dial is fixed
in position.
• Howtoinstall
1HANDS
• Howtoinstall
2DIAL
* Match the polarity of the ROTORs for STOPWATCH and
ALARM, and then install the hands.
Check that the voltage of rechargeable battery exceeds 1.2 V
and the watch is working.
*Crown position: normal position.
Short-circuit in touching the AC pattern and the rechargeable
battery guard with tweezers (refer to the Fig. 1).
In order to match the polarity of the ROTORs, short-circuit in
touching the pattern A and the rechargeable battery guard with
tweezers (refer to the Fig. 2).
Install the CHRONOGRAPH minute hand, the alarm hour hand
and the alarm minute hand at “0” position.
Pull out the crown to the second position, then turn it clockwise
in order to change the calendar.
Install the small second hand, the 24-hour hand (V174A), the
hour hand, the minute hand and the CHRONOGRAPH second
hand at “0” position.
pattern A
Fig. 1
Fig. 2

④SOLAR CELL
⑤HOLDING RING FOR DIAL
* It is not necessary to separate the SOLAR CELL and the HOLDING RING FOR DIAL except in the case
that a part needs to be replaced.
• DisassemblingandReassemblingofHOLDINGRINGFORDIAL
<Disassembling>
1. The HOLDING RING FOR DIAL is fixed to the movement by the
hooking portion at 4 o’clock and 11 o’clock positions.
2. Insert the tip of a screwdriver into the gap between the hooking
portion and main plate as shown with arrow marks in the
illustration to release the hooking portion from the main plate.
<Reassembling>
1. Set the 2 hooking portions to 4 o’clock and 11 o’clock positions
as shown in the illustration.
2. Gently push the hooking positions of HOLDING RING FOR
DIAL so that they catch the main plate securely.
TECHNICAL GUIDE Cal. V172A/V174A
11/ 2 5
REMARKS ON DISASSEMBLING AND REASSEMBLING THE MOVEMENT
3SPACER FOR SOLAR CELL
Set the notched portions of the SPACER FOR SOLAR CELL to
the guide posts (5 posts) of the HOLDING RING FOR DIAL, and
check that the dial is fixed in position.
• Howtoinstall

• DisassemblingandReassemblingofSOLARCELL
* Do not apply excessive force to the SOLAR CELL.
<Disassembling>
As there are 2 connection parts of the HOLDING RING FOR
DIAL,release them side by side.
<Assembling>
Set the SOLAR CELL to 3 guide posts, and assemble it to the
HOLDING RING FOR DIAL by expanding the hooking portion
as shown in the illustlation.
⑧DATE DIAL GUARD
• Lubrication
Lubricate the DATE JUMPER and the tip of the DATE DIAL.
AO-3
TECHNICAL GUIDE Cal. V172A/V174A
12/25

㉔RECHARGEABLE BATTERY GUARD
• Assembling
Set the RECHARGEABLE BATTERY GUARD to the guide posts (2 posts), and then tighten the
rechargeable battery guard screws (3 pcs.).
SCREW
SCREW
SCREW
GUIDE POST
GUIDE POST
TECHNICAL GUIDE Cal. V172A/V174A
13/25

㉕RECHARGEABLE BATTERY BLOCK
• Assembling
Set the notched portion of the RECHARGEABLE BATTERY BLOCK to the guide post, and check
that the hooking portion of the RECHARGEABLE BATTERY BLOCK touches the (-) output terminal
of the CIRCUIT BLOCK.
HOOKING PORTION
GUIDE POST
(-) INPUT TERMINAL
TECHNICAL GUIDE Cal. V172A/V174A
14/25

㉗CIRCUIT BLOCK COVER
• Disassembling
1. Loosen the 3 CIRCUIT BLOCK COVER SCREWs.
2. Release the 4 hooking portions of the CIRCUIT BLOCK COVER (indicated by the arrows in the
illustration below.)
• Assembling
1. Have the four hooking portions of the CIRCUIT BLOCK COVER (indicated by the arrows in the
illustration below) catch the movement securely. In doing so, check if the circuit block is set properly
to guide posts “a” and “b,” and reset it in position if necessary.
2. Tighten the 3 CIRCUIT BLOCK COVER SCREWs. When tightening the screws, take care not to cut
the coil.
c
b
a
SCREW
SCREW
SCREW
㉘CONDUCTING PLATE
• Assembling
Put the CONDUCTING PLATE on the CIRCUIT
BLOCK as shown in the illustration, and secure
it with the 2 guide posts.
GUIDE POST
GUIDE POST
TECHNICAL GUIDE Cal. V172A/V174A
15/25

㉙SECOND HOLD SPRING
• Reassembly
Slide a part of the SECOND HOLD SPRING under the TRAIN WHEEL BRIDGE.
㉚CIRCUIT BLOCK
• Disassembling
Taking care not to damage the CIRCUIT BLOCK,
remove it from the posts of the TRAIN WHEEL
BRIDGE and the screw pins of the MAIN PLATE
(refer to a, b, c, d and e in the illustration).
• Reassembling
Set the guide holes of the CIRCUIT BLOCK
(refer to a, b, c, d and e in the illustration) to
the posts of the TRAIN WHEEL BRIDGE and the
screw pins of the MAIN PLATE.
ｅａ
ｂ
ｃ
ｄ
TECHNICAL GUIDE Cal. V172A/V174A
16/25

㉜PIN FOR TRAIN WHEEL BRIDGE
• Disassembling
Turn the PIN FOR TRAIN WHEEL BRIDGE counter clockwise by 90 degrees, and loosen it.
• Reassembling
Set the PIN FOR TRAIN WHEEL BRIDGE as shown in the illustration, and tighten it by turning
clockwise by 90 degrees. (Refer to the Fig. 1.)
<Lubrication>
After fastening the PIN FOR TRAIN WHEEL BRIDGE, lubricate the upper part of the pivots of the
following parts (refer to the Fig. 2):
 • 4ROTORs:AO-2
 • MINUTEWHEEL:AO-3
 • SMALLSECONDHAND:AO-3
 • MINUTECOUNTINGWHEEL:AO-3
 • ALARMMINUTEWHEEL:AO-3
 • 1/5-SECONDCOUNTINGWHEEL:AO-3
ＡＯ2
ＡＯ3
TECHNICAL GUIDE Cal. V172A/V174A
17/25
㉝TRAIN WHEEL BRIDGE
• Assembling
1. Check the setting positions of the WHEELs and ROTORs carefully. Be sure to check that lower
pivot of rotors are set to the MAIN PLATE properly.
2. Pull out the SETTING STEM to the 1st click position.
3. Install the TRAIN WHEEL BRIDGE without pushing hardly. If the BRIDGE can not be installed
smoothly, recheck the setting position of WHEELs and ROTORs as some parts may be set in
the wrong position.
<Setting position>
Refer to the illustration in the next page.
Fig. 1
Fig. 2

TECHNICAL GUIDE Cal. V172A/V174A
18/25
● How to identify the gear train parts
35 SMALL SECOND
WHEEL
0240 511
38 FIFTH WHEEL AND
PINION
0701 581
39 FIRST INTERMEDIATE
1/5-SECOND
COUNTING WHEEL
0885 590
41 INTERMEDIATE
MINUTE COUNTING
WHEEL
0950 590
42 MINUTE COUNTING
WHEEL
0902 500
45 CENTER WHEEL
FOR ALARM
0902 502
34 1/5-SECOND
COUNTING WHEEL
0888 501
36 FORTH WHEEL AND
PINION
0241 583
37 THIRD WHEEL AND
PINION
0231 580
40 SECOND INTERMEDIATE
1/5-SESOND COUNTING
WHEEL
0885 591
43 MINUTE WHEEL
0261 580
46 MINUTE WHEEL FOR
ALARM
0261 582
44 INTERMEDIATE
ALARM WHEEL
0950 590
53 ROTOR
4146 710
54 CHRONOGRAPH ROTOR
FOR 1/5 SECOND
4146 710
55 MINUTE COUNTING
ROTOR
4146 710
52 ROTOR FOR ALARM
4146 710
58 SETTING WHEEL
0281 580
62 CENTER WHEEL
SPRING
4283 581
Note ◆The INTERMEDIATE MINUTE COUNTING WHEEL and the INTERMEDIATE ALARM WHEEL are the same.
◆ThefollowingROTORsarethesame.•ROTOR
•CHRONOGRAPHROTORFORMINUTE
•ALARMROTOR
•CHRONOGRAPHROTORFOR1/5SECOND

TECHNICAL GUIDE Cal. V172A/V174A
19/25
51 SWITCH LEVER A
56 SETTING LEVER
57 YOKE
61 TRAIN WHEEL SETTING LEVER
59 WINDING STEM
63 CENTER WHEEL AND PINION
69 MAIN PLATE
AＯ 3
Ｓ−６
ＡＯ3
ＡＯ2
● How to lubricate

TECHNICAL GUIDE Cal. V172A/V174A
20/25
l CHECKING THE ELECTRICAL CHARACTERISTICS
<Coil resistance>
㊽ COIL BLOCK (4002 541) between 1.90 and 2.30 kΩ
㊾ COIL BLOCK FOR CHRONOGRAPH 1/5 SECOND (4002 541) between 1.90 and 2.30 kΩ
㊿ COIL BLOCK FOR CHRONOGRAPH MINUTE (4002 542) between 1.75 and 2.15 kΩ
㊼ COIL BLOCK FOR ALARM (4002 542) between 1.75 and 2.5 kΩ
<How to measure the current consumption for the whole movement>
1) Remove ⑤HOLDING RING FOR DIAL, ④SOLAR CELL and ㉕RECHARGEABLE BATTERY BLOCK
from the movement.
2) Set ㉔RECHARGEABLE BATTERY GUARD, and then tighten 3 screws.
3) Connect the (-) probe to the (-) input terminal of ㊽COIL BLOCK and the (+) probe to the (+) input
terminal of ㊽COIL BLOCK as illustration.
4) Touch the AC terminal of the CIRCUIT BLOCK and the switch spring with the tweezers to reset the
circuit as illustrated.
* When measuring the current consumption using
the SEIKO digital multi-tester (S-860), use the
range of 40 μA of SUPPLY V (=1.55 V) & 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 0.95 μA.
REMARKS ON INSPECTION AND MEASUREMENT