Seiko 7T62A Quick start guide

EMMY WATCH
VINTAGE RESTORATIONS
Seiko 7T62A,7T92A,7T94A Movement Parts (3)
Compiled by EmmyWatch - https.//www.emmywatch.com

13/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
III. REMARKS ON DISASSEMBLING AND REASSEMBLING
•Caution for disassembling
•How to install
●Hands
●Dial
•Caution for disassembling
1 Pin for date dial guard
• How to remove • How to install
1. Turn the pin 90-degree counterclockwise to
loosen the pin using a screwdriver.
2. Pick up the pin using rodico.
1. Set the pin securely into the groove.
2. Turn the pin 90-degree clockwise to fix the
pin using a screwdriver.
Notes:
*Do not turn the pin more than 90-degree in either direction. Take care so as not to break the plastic
parts.
*Do not turn the pin forcibly.
* Use a screwdriver of an appropriate size .
The hour wheel is made of engineering plastics. When pulling out the hour hand, take care not to
damage the hour wheel.
1) Pull out the crown with winding stem to the second click. Then, turn the crown clockwise to turn
the time hands also clockwise.
2) Stop turning the crown when the date changes to the next.
3) 7T62: Install the stopwatch minute hand, alarm hour and minute hands so that they point exactly
to the 12 o’clock position.
7T92: Install the stopwatch 1/20-second hand, stopwatch hour and minute hands so that they
point exactly to the “0” position.
7T94: Install stopwatch minute hand so that it points exactly to the “0” position.
4) Install the small second, hour and minute hands so that they point exactly to the 12 o’clock
position.
5) Install the stopwatch hand so that it points exactly to the “0” position of the stopwatch scale.
*After installing the hands, be sure to check that they move smoothly without interfering with one
another.
When disassembling the dial, take care not to bend the dial leg. Raise the portions around the dial
legs by turns gradually to remove the dial.
rodico

14/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
Date jumper
• Lubricating
After installing the pins for date dial guard, lubricate the wheel edge of both the date driving wheel and
date dial.
AO-3 (or MS-A)
8Hour wheel
When installing the hour wheel, check that it engages with the pinion of the minute wheel.
10 Battery clamp
When installing the battery clamp, set it securely to the two hooking portions of the movement.
Protruded portion
Guide post

15/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
13 Circuit block cover
Screw
• How to remove
1) Loosen the four circuit block cover screws.
2) Release the four hooking portions of the circuit block cover (indicated by the arrows in the
illustration below.)
Screw
Screw
“b” portion
“a” portion
•How to install
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 four circuit block cover screws. When tightening the screws, take care not to cut the coil.
14 Friction spring for second counting
•Setting position
To set the friction spring for second counting,
slip it into the gap under the train wheel
bridge.

16/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
a
b
c
d
e
15 Circuit block
•Caution for disassembling
•How to install
The circuit block is fixed to the train wheel bridge with the guide pins (“a”,“b”,“c”,“d” and “e” in
the illustration shown below). When removing the circuit block from the guide pins, take care not
to damage the circuit block.
Have the guide holes of the circuit block (“a”,“b”,“c”,“d” and “e” portions in the illustration)
securely caught by the guide pins of the train wheel bridge and the guide tubes of the main plate.

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17/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
19 Train wheel bridge
•How to install
AO-3 (or MS-A)
AO-2 (or MS-F)
18 Pin for train wheel bridge
•How to remove
Turn the pin 90 degrees counterclockwise with a screwdriver to loosen it.
•How to install
Pin for train wheel bridge
• Lubricating
After installing the pin, lubricate the upper pivot of the parts as indicated in the table below.
CAL. 7T62A
CAL. 7T92A
CAL. 7T94A
Minute wheel
Small second wheel
Minute counting wheel
Center wheel for alarm
Second counting wheel
Minute wheel
Small second wheel
Second counting wheel (1/20)
Second counting wheel
Minute wheel
Small second wheel
Minute counting wheel
AO-3 (or MS-A)
Chronograph rotor for second
Chronograph rotor for minute
Alarm rotor
Step rotor
Chronograph rotor for second (1/20)
Chronograph rotor for second
Chronograph rotor for minute
Step rotor
Chronograph rotor for second
Chronograph rotor for minute
Step rotor
AO-2 (or MS-F)
Set the pin in the direction as shown below. Then, turn it 90 degrees clockwise with a screwdriver
to fix it.
Before installing the train wheel bridge, carefully check the setting positions of the wheels and
rotors. Be sure to check that each rotor has a lower pivot attached securely.
If the wheels and rotors are all set in position with the winding stem with crown at the first click,
the train wheel bridge can be installed smoothly. There is no need to press down the train wheel
bridge.
If the train wheel bridge will not be seated in position smoothly, the other parts must be set in the
wrong position. Check their setting positions.

18/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
●Wheels and pinions
Notes:
1.
CAL. 7T62A:
Intermediate minute counting wheel and intermediate alarm wheel can be used interchangeably.
CAL. 7T92A:
Intermediate wheel for second counting (1/20) and intermediate minute counting wheel can be used
interchangerably.
2. The following rotors for each caliber can be used interchangeably:
CAL. 7T62A
•Chronograph rotor for second (1/5)
• Chronograph rotor for minute
•Alarm rotor
• Step rotor
CAL. 7T92A
•Chronograph rotor for second (1/20)
• Chronograph rotor for second
•Chronograph rotor for minute
•Step rotor
CAL. 7T94A
•Chronograph rotor for second (1/5)
• Chronograph rotor for minute
•Step rotor
• Setting position
See the illustration on the next page.

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19/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
<7T62A only>
<7T62A only>
<7T62A only>
The illustrations refer only to Cal. 7T62A & 7T94A.
27 0261 580
Minute wheel
20 0888 582
Second counting wheel
44 0281 580
Setting wheel
47 4283 581
Sp ac er f or c en te r
wheel & pinion
40 4146 710
Chronograph rotor for
minute
26 0885 591
Second intermediate
wh ee l fo r se co nd
counting
28 0950 590
I n t e r m e d i a t e m i n u t e
counting wheel
39 4146 710
Chronograph rotor for
second
25 0885 590
First intermediate wheel
for second counting
21 0240 580
Small second wheel
24 0701 580
Fifth wheel & pinion
38 4146 710
Step rotor
22 0241 583
Fourth wheel & pinion
23 0231 580
Third wheel & pinion
32 0261 582
Minute wheel for alarm
30 0950 590 <7T62A>
Intermediate alarm wheel
31 0270 582 <7T62A>
Center wheel for alarm
29 0902 580
Minute counting wheel
37 4146 710
Alarm rotor
0240 582 <7T94A>
Small second wheel
0817 508 <7T94A>
Intermediate
small second wheel
21a 21b

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20/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
The illustrations refer only to Cal. 7T92A.
23 0231 580
Third wheel & pinion
22 0241 583
Fourth wheel & pinion
31 0270 582
Minute counting wheel
27 0261 580
Minute wheel
20 0888 582
Second counting wheel
30 0950 590
Intermediate minute
counting wheel
32 0261 582
Intermediate wheel for
hour counting
28 0950 590
Intermediate wheel for
second counting (1/20)
25 0885 594
First intermediate wheel
for second counting
21 0240 580
Small second wheel
39 4146 710
Chronograph rotor for
second
44 0281 580
Setting wheel
38 4146 710
Step rotor
40 4146 710
Chronograph rotor for
second (1/20)
47 4283 581
Spacer for center wheel
& pinion
29 0902 580
Second counting wheel
(1/20)
26 0885 595
Second intermediate
w h e e l f o r s e c o n d
counting
37 4146 710
Chronograph rotor for
minute
24 0701 580
Fifth wheel & pinion

21/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
•Setting position and lubricating
41 Switch lever (A)
42 Setting lever
43 Yoke
49 Train wheel setting lever
48 Center wheel and pinion
45 Winding stem
Train wheel setting lever
Yoke
Setting lever
Switch lever (A)
AO-3 (or MS-A)
SEIKO Watch Oil S-6

()
22/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
55 Main plate
AO-3 (or MS-A)
AO-2 (or MS-F)
SEIKO Watch Oil S-6
• Lubricating
Switch lever axle for switch lever (B)

23/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
●Coil block resistance
IV. VALUE CHECKING
Coil block (A)
Coil block for chronograph second
Coil block for chronograph minute (Cal. 7T62A)
Coil block for second counting (1/20) (Cal. 7T92A)
Coil block for alarm (Cal. 7T62A)
Coil block for chronograph (Cal. 7T92A)
1.70 KW~ 2.60 KW
1.70 KW~ 2.60 KW
1.80 KW~ 2.40 KW
1.80 KW~ 2.40 KW
●Upconverter coil resistance : 150 W~ 180 W
●Current consumption
When measuring the current consumption with SEIKO Multi-Tester S-860,
select the measurement range as follows:
Less than 1.10 m A (with 1.55 V supplied from a battery)
(when the stopwatch is not used)
Less than 0.20
m A (with 1.55 V supplied from a battery)
For the whole movement
For the circuit block alone
Use the range of 40 mA of SUPPLY V (= 1.55 V) & GATE TIME (2 S) For the whole movement
For the circuit block alone
Use the range of 4 mA of SUPPLY V (= 1.55 V) & GATE TIME (2 S)
V. FUNCTION CHECKING
Follow the procedure in “II. NECESSARY PROCEDURE AFTER BATTERY CHANGE” to set the
time hands and reset the stopwatch hands to the “0” position.
*Before checking the stopwatch function, reset the stopwatch hands to the “0” position
following the procedure in “II. NECESSARY PROCEDURE AFTER BATTERY CHANGE.”
*Check that the crown is at the normal position. If not, the stopwatch operation cannot be made.
●TIME SETTING AND STOPWATCH HAND POSITION ADJUSTMENT
●STOPWATCH FUNCTION

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24/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
CAL. 7T62A CAL. 7T92A CAL. 7T94A
2. Checking for Split Time Measurement
Press to start the measurement.
A
A
B
Press repeatedly to check
if the stopwatch 1/5
second hand starts and
stops with each press.
Press to check if all the
stopwatch hands return
to the “0” position.
Check if the stopwatch
minute hand starts
m o v i n g a s t h e
accumulated elapsed
time exceeds one minute.
P r e s s t o s t o p t h e
measurement.
A
A
A
A
A
B
Press repeatedly to check
if the stopwatch 1/20
second hand starts and
stops with each press.
Press to check if all the
stopwatch hands return
to the “0” position.
Check if the stopwatch
hour and minute hands
sta rt moving as the
accumulated elapsed
time exceeds one minute.
P r e s s t o s t o p t h e
measurement.
B
A
B
B
B
A
B
B
1. Checking for Standard Measurement/Accumulated Elapsed Time Measurement
Press repeatedly to check
if the stopwatch 1/5
second hand starts and
stops with each press.
Press to check if all the
stopwatch hands return
to the “0” position.
Check if the stopwatch
minute hand starts
m o v i n g a s t h e
accumulated elapsed
time exceeds one minute.
P r e s s t o s t o p t h e
measurement.
Press to check if the stopwatch hands stop to indicate the split time.
Press to check if the hands move quickly to indicate the elapsed time and restart the measurement.
Press repeatedly to check if the split time is measured and released with each press.
Press to stop the measurement.
Press to check if all the stopwatch hands return to the “0” position.
Note for the stopwatch 1/20 second hand for Cal. 7T92A:
*After the stopwatch is started, the stopwatch 1/20-second hand automatically stops and stays at the “0”
position if the measurement exceeds 10 minutes. When the measurement is stopped or split time is
measured, it moves to indicate the elapsed 1/20 seconds.
Also, after the stopwatch is restarted or split time is released, the stopwatch 1/20-second hand
automatically stops and stays at the “0” position if the measurement exceeds another 10 minutes.

25/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
❖To Set the Alarm Time
Pull out to the 1st click.
Press repeatedly to set the alarm hands to the desired alarm time.
*With each press, they move by one minute. They move quickly if the button is kept pressed. They stop when
they reach the current time. Release and press the button, and the hands will start moving again.
*The single-time alarm cannot be set for a time more than 12 hours ahead of the current time.
❖ To Readjust the Designated Alarm Time
Pull out to the 1st click.
CROWN
Press repeatedly to set the alarm hands to the desired alarm time.
Push back in to the normal position.
CROWN
B
B
CROWN
CROWN Push back in to the normal position.
•Before checking the alarm function, set the time and alarm hands to the current time following the
procedure in “II. NECESSARY PROCEDURE AFTER BATTERY CHANGE.”
●ALARM FUNCTION (Only for Cal. 7T62A)
▼
*At the designated alarm time, the alarm rings for 20 seconds and stops. To stop it manually, press button “A”
or “B”.
*After the alarm rings, the alarm minute hand starts moving at one-minute intervals, then the alarm hands indicate
the current time.
▼
▼
▼
❖
To Cancel the Alarm
Pull out to the 1st click.
CROWN
Press repeatedly to set the alarm hands to the current time.
Push back in to the normal position.
CROWN
B
▼
▼

26/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
Movement
VI. TROUBLESHOOTING
The watch stops
operating.
The battery has been depleted. Measure the battery voltage.
Replace the battery with a new
one.
The hour wheel and the pinion
of the minute wheel are not
properly engaged. (Or the teeth
of the hour wheel and/or minute
wheel has been broken.)
Check the relevant parts, and
replace the damaged parts with
new ones.
The hooking portions of the
circuit block cover are not
properly engaged, resulting in
poor conductivity.
Securely attach the hooks of
the circuit block cover to the
main plate.
The coil is broken. M e a s u r e t h e c o i l b l o c k
resistance. Replace the coil with
a new one.
One or more wheels have been
contaminated with dirt, dust or
other particles.
An excessive amount of oil in
the movement has caused
adhesive forces among the
parts. (wringing)
Remove dirt or dust and clean
the contaminated wheels. Be
careful so as not to damage the
teeth of the plastic parts while
cleaning.
The current consumption
for the whole movement
exceeds the standard
value.
C h e c k t h e r o t a t i o n a n d
engagement of the date dial.
Bend the date dial downward
to adjust the clearance. Or
replace the date dial with a new
one.
Dirt, dust or foreign particles
are adhered to the movement.
Remove dirt, dust or foreign
particles and clean the
movement.
The driving pulse is generated
in order to compensate the
excessive load applied to the
wheels. (The oil is deteriorated,
leaked or ran out.)
If the current consumption for
the circuit block alone is within
the standard value range,
ov e rh a ul a n d cl e an t h e
movement parts, and then
make the measurement again.
The current consumption
for the circuit block alone
exceeds the standard
value.
The light from outside the
movement is affecting the
measurement.
Shut out the light, and make the
measurement again.
There is a defect in the IC
(integrated circuit).
Replace the circuit block with a
new one.
The date dial shows an
abnormal movement.
The date dial has become
improperly engaged with the
d a t e d r i v i n g w h e e l o r
disengaged from the date
driving wheel.
T h e d a t e d o e s n o t
change.
T h e d a t e j u m p e r h a s
disengaged.
Symptom Possible causes Solutions
The date dial does not
move.

SEIKO WATCH CORPORATION
27/27
TECHNICAL GUIDE Cal. 7T62A/7T92A/7T94A
©2002-2006 by
Stopwatch/
Alarm
One or more hands of
the stopwatch or alarm
have stopped moving or
show an abnormal
movement.
The relevant coil is broken. M e a s u r e t h e c o i l b l o c k
resistance. Replace the coil with
a new one if necessary.
The excessive load is being
applied to the chronograph
wheels due to dust or foreign
particles adhered to them or oil
starvation.
Clean the relevant parts and
lubricate with an adequate
amount of oil.
The step motor shows
an abnormal movement
.
There is a crack on the circuit
block switch pattern.
Replace the circuit block with a
new one.
The buttons do not
operate normally.
The amount of oil around the
buttons is insufficient.
Clean the buttons and lubricate
appropriately.
The circuit block pattern has
been broken or bended.
Adjust the circuit block pattern
or replace the circuit block with
a new one.
The alarm does not
sound. (For 7T62A only)
The Piezoelectric element is
broken or out of alignment.
The upconverter coil is broken. Replace the circuit block with a
new one.
The alarm sound is too
small. (For 7T62A only)
The crown falls off. The winding stem is not securely
installed. (The setting lever and
yoke are disengaged.)
Check the main plate, winding
stem, setting lever and yoke.
Replace the defective parts with
new ones.
The current consumption
exceeds the standard
value.
The excessive load is being
applied due to frictions among
the hour, minute and
chronograph hands.
Small amount of water/
blur inside of the glass
persists.
Water resistance is deteriorated.
The watch has been subjected
to water pressure that exceeds
the guaranteed degree.
Investigate the causes to take
necessary measures, while
cleaning inside of the watch.
Remount the piezoelectric
element or replace it with a new
one.
Replace the stator with a new
one.
Adjust or remount the relevant
hands.
Symptom Possible causes Solutions
Exterior
parts
The step motor has been
diformed.