Seiko 7K52A Installer manual

1
PARTS CATALOGUE / TECHNICAL GUIDE
Cal. 7K52A
CAUTION
The SEIKO SCUBA Cal. 7K52A is intended for use in diving, an inherently hazardous
form of recreation. Therefore, it is absolutely essential that you strictly observe all
instructions for the repairing and checking of the SEIKO SCUBA watch described in
this guide.
Take the greatest possible care when repairing and checking the depth measurement
function as well as the water resistant quality of this watch, because the depth meas-
urement serves as a guideline when the user is making a dive.
In addition, you must fully understand the following:
• This watch is for use in recreational scuba diving (no-decompression diving), and
is not for decompression diving, saturation diving or diving at altitudes.
• It is for use in water having a temperature range of 0°C to 40°C.
• It can measure the depth of sea water correctly, whose specific gravity is 1.025,
but not that of fresh water.
It is recommended that you explain to users the specifications of the watch, limits of
use and cautions on improper use as required. In doing so, refer to the “CAUTION”
included at the beginning of the instruction booklet of the watch.

Cal. 7K52A
2
[SPECIFICATIONS]
Item
Movement
Indication system
Depth measurement part
Time Alarm part
Hour hand
Minute hand
Small second hand
1/10 m depth hand
Diving time hand
Depth hand (Up to 55m)
Maximum depth hand
(advanced by depth hand)
Alarm hour hand
Alarm minute hand
Driving system Step motor (4 pcs.)
0 °C ~ 40 °C
Influence of temperature change of 20 °C
Within ±1 m
Loss/gain Monthly rate at normal temperature range : less than 15 seconds
Regulation system Nil
Cal. No. 7K52A
Temperature range providing warrantable
accuracy
Within ±(displayed value x 3 % + 0.5 m)
Movement
size
Outside diameter
Casing diameter
Height
ø31.0 mm
ø30.0 mm
5.9 mm
•Electronic circuit reset switch
•Train wheel setting device
•Battery life indicator
•Date calendar
•Instant setting device for date calendar
•Full automatic measurement of div-
ing data
•Recall of log data
•Depth warning function
•Single-time alarm function
Additional functions
Accuracy of the depth
measurement
Battery
Measuring gate by quartz tester
In sea water at a stable temperature
(x 1.0)
Jewels 0 jewel
Use 10-second gate.
Voltage : 3.0 V
Battery life is approximately 2 years.
SEIKO CR2016, Maxell CR2016, Sanyo CR2016, Matsushita CR2016,
Eveready CR2016

Cal. 7K52A
Please see the remarks on the following pages.
Disassembling procedures Figs. : 1 →101
Reassembling procedures Figs. : 101 →1
Lubricating: Types of oil Oil quantity
Moebius A Normal quantity
SEIKO Watch Oil S-6 Extremely small
Silicone oil 500,000 c.s.
5 Movement
PARTS CATALOGUE
Piezoelectric element
3 Case ring
21 Dial
6 Gasket for sensor unit
10 Button at the 8 o’clock side
14 Hour hand
13 Minute hand
12 Diving time hand
16 Depth hand
17 1/10 m depth hand
18 Small second hand
19 Alarm minute hand
20 Alarm hour hand
15 Maximum depth hand
22 0491 623
Dial washer
Cal. 7K52A
11 case
3
7 Button spring clip
9 Button at the 10
o’clock side
8 Button at the 2 o’clock side
23 gasket
4 Crown (with winding stem)
Lubricating of some parts is shown in “III. REMARKS ON DISASSEMBLING AND REASSEMBLING”.
1 Case back
2 Case back gasket
Insulator
0494696
(Revised: 2007/09/13
changed the part name
to Insulator from gasket)

Cal. 7K52A
4
30 1002 619
Maximum depth hand wheel
PARTS CATALOGUE
0012 354
• Circuit block cover A screw (3 pcs.)
• Circuit block cover B screw (1 pc.)
• Date dial guard screw (2 pcs.)
0022 230
• Battery clamp screw (2 pcs.)
• Sensor clamp screw (1 pc.)
• Anti-magnetic shield plate
screw (2 pcs.)
Lubricating of some parts is shown in “III. REMARKS ON DISASSEMBLING AND REASSEMBLING”.
Please see the remarks on the following pages.
31 Date dial
24 0012 354
Date dial guard screw
25 4283 612
Depth hand wheel clamp
28 0808 606
Date dial guard
29 1018 610
Setting lever spring for maximum
depth hand
32 0012 354
Anti-magnetic shield plate screw
34 0810 606
Date jumper
39 0271 614
Hour wheel for alarm
• Spacer for circuit block screw (1 pc.)
27 1017 610
Setting lever for maximum
depth hand
38 0962 580
First intermediate wheel for
calendar correction
26 1002 618
Depth hand wheel
33 4259 691
Anti-magnetic shield plate
40 0271 616
Hour wheel
37 0962 590
Second intermediate wheel for
calendar correction
35 0802 605
Date driving wheel
36 0737 590
Calendar corrector setting wheel

Cal. 7K52A
47 4000 695
Sensor circuit block
Lubricating of some parts is shown in “III. REMARKS ON DISASSEMBLING AND REASSEMBLING”.
Please see the remarks on the following pages.
52 4216 691
Insulator for circuit
block
54 4457 813
Circuit block cover (B)
58 4000 696
Circuit block
PARTS CATALOGUE
43 Battery
44 4531 692
Circuit block guard
45 0022 230
Sensor clamp screw
46 4283 611
Sensor clamp
42 4225 692
Battery clamp
(with AC comment sheet)
41 0022 230
Battery clamp
screw
48 0022 230
Spacer for circuit
block screw
49 0439 612
Spacer for circuit block
50 4246 693
Buzzer lead terminal
51 4000 694
A/D circuit block
53 0012 354
Circuit block cover
(B) screw
55 0012 354
Circuit block cover (A)
screw
59 4270 690
Battery connection (-)
60 4246 691
Switch lead terminal
(A)
56 4457 812
Circuit block cover (A)
57 0396 610
Friction spring for
second counting
5