Casio LWQ-160DE Troubleshooting guide

SERVICE MANUAL
& PARTS LIST
(WITHOUT PRICE)
QW-4791
MODULE NO.
REF. NO. S/M-998
AUG. 2007
LWQ-160DE LWQ-160LE
Ver.1 : May. 2008

CONTENTS
Page
1. SPECIFICATIONS: MODULE QW-4791 ..................................................... 1
2. DRAWINGS: MODULE QW-4791
2-1. CHECKING TERMINALS AND COMPONENTS ............................................ 2
3. EXPLODED VIEW: MODULE QW-4791 ..................................................... 3
4. PARTS LIST: MODULE QW-4791 ............................................................... 4
5. PRECAUTIONS FOR REPAIR: MODULE QW-4791
5-1. AC (ALL CLEAR) AND REMOVING OF MODULE ....................................... 6
5-2. MEASURING CURRENT CONSUMPTION ................................................... 6
5-3. ACCURACY CHECKING ............................................................................... 7
5-4. TIME CALIBRATION SIGNAL TEST MODE .................................................. 8
APPENDIX
Operation Guide 4791

— 1 —
1. SPECIFICATIONS: MODULE QW-4791
Item Detail
Battery
Battery life
Current consumption
Alarm system
Accuracy
Accuracy setting system
Accuracy checking
Functions:
ESR920W
Approx. 2 years
0.24 µA maximum:µA maximum
See page 6
-
±20 sec./month
Chip capacitor selection
See page 7
• Time calibration signal reception
Auto receive
Manual receive
• Time Calibration Signal
Receivable Time Calibration Signals
Fort Collins, Colorado (Call Sign: WWVD, Frequency : 60kHz)
Rugby, England (Call Sign: MSF, Frequency: 60kHz)
Mainflingen, Germany (Call Sign: DCF77, Frequency: 77.5kHz)
Fukushima, Japan (Call Sign: JJY, Frequency: 40kHz)
Fukuoka/Saga, Japan (Call Sign: JJY, Frequency: 60kHz)
• Regular timekeeping:
Analog: 3 hands (Hour, minutes, seconds)

— 2 —
2. DRAWINGS: MODULE QW-4791
2-1. CHECKING TERMINALS AND COMPONENTS
R1
R3 DIO13
DIO7 DIO6
XT
VOSC
GND
XT
XT
XTB
VCH GND
VOSC
GND
VDD2
GND
GND
T4
T3
AC
O6
PM_RES
DIO4 O5
O3
VDD2
O4
VCH
T1
DIO3
DIO13
R1
R2
T2
DIO7
O1
O2
SCR
R2
R3
GND
DIO5
VSC
DIO2
DIO1
SCIN
VCC
GND
VSC
GND
GND
GND
GND
GND
DIO14
GND
GND GND
GNDB
P2'
FET-D
P2
GNDB
GND
GND
VOSC
AC
VDD2
DIO4
O6
P2'
P1' P1'
FET-S'
P1'
P2'
P2 FET-S
VCC
VSC
P1' FET-S'
VDD2
DIO1
SCIN
GND
GND SCR
DIO2
P5 P7
P7
P4
GND
Ccp
Ccp P9
P7
P5
VSC
VDD2
O5
O1
O4
P1
DIO12
DIO3
VCH
PM_RES
GND
SCIN
SCIN
OSCILLATOR/CRYSTAL
2. PCB ASS'Y
(76410798)
TAPE/ADHESIVE 2306
Short pad for switching modules
D1014-GND: Open (No Soldering)
D1013-GND: Short (Soldering)

— 3 —
3. EXPLODED VIEW: MODULE QW-4791
17 (72270294)
2 (76410798)
PCB ass'y
8 (10212747)
9 (10209123)
18 (10209118)
1 (76409228)
12 (10209124)
11 (10009244)
15 (10212751)
13 (10234346)
6 (10212752)
3 (19101199)
Battery storage (ESR920W)
5 (10209109)
16 (10212748)
13 (10234346)
7 (10237097)
14 (10212750)
10 (10140782)
4 (10209108)
11 (10009244)

4. PARTS LIST: MODULE
Q
W-4791
Q
W-4791A
T
1
Q
W-4791AT-01
Note: 1. Prices and s
p
ecifications are sub
j
ect to chan
g
e without
p
rior notice.
2. S
p
are
p
arts are classified as follows accordin
g
to their im
p
ortance in after-sales service.
A
Rank ----------------------------------------
-
Im
p
ortant
C Rank ----------------------------------------
-
Not Im
p
ortant
3. Batteries in Bulk
p
ack on the tra
y
will be su
pp
lied from our Overseas S
p
are Parts Section under char
g
e basis.
Batteries in Blister
p
ack will be su
pp
lied from our Sales De
p
artment.
4. As for order/su
pp
l
y
of s
p
are
p
arts, refer to the se
p
arate
p
ublication "GUIDE BOOK for s
p
are
p
arts su
pp
l
y
".
A
ttention to order
1. The most of normal re
p
air or initial re
p
air within 1
y
ear since released month can be done b
y
main
p
arts.
2. Minor
p
arts should be ordered carefull
y
in consideration of the actual usa
g
e of
y
our re
p
air and
y
our technical skills.
3. Main
p
arts should be ordered and stocked a
pp
ro
p
riatel
y
in consideration of
y
our
p
arts usa
g
e anre re
p
air usa
g
e for
similar models.
MAIN PARTS
Item Code No. Parts Name S
p
ecification Q'TY R
1
76410781 MODULE/WITH MOVEMENT QW-4791AT-01TK 1
A
1 76409228
A
NALOG BLOCK QW-4323MV-82TK 1
A
(
RJQ528359*001V01
)
2 76410798 PCB ASS'
Y
RJQ538072*001V01TK 1
A
MINOR PARTS
Item Code No. Parts Name S
p
ecification Q'TY R
1
3 19101199 BATTERY/STORAGE ESR920W 1 C
4 10209108 COIL ASS'Y 4323-1 RJQ526939*001V02 1 C
5 10209109 COIL ASS'Y 4323-2 RJQ526940*001V02 1 C
6 10212752 CUSHION 4323-1 RJQ527451-001V01 1 C
7 10237097 CUSHION 4323-2 RJQ527452-001V02 1 C
8 10212747 HOLDER 4323 RJQ527417-001V01 1 C
9 10209123 HOLDER RJQ526931-001V01 1 C
/HOUR WHEEL 4323
10 10140782 LABEL 2815 RJQ517198-001V02 1 C
11 10009244 SCREW 2323 Q465649-1 3 C
12 10209124 SCREW 4323 RJQ526942-001V01 2 C
13 10234346 SCREW 4329 RJQ532242-001V01 2 C
14 10212750 SHEET/INSULATION 4323-2 RJQ527449-001V01 1 C
15 10212751 TAPE/ADHESIVE 4323 RJQ527454-001V01 1 C
16 10212748 TERMINAL/BATTERY
(
+
)
4323 RJQ527422-001V01 1 C
Notes: R - Rank
A: Im
p
ortant
C: Not Im
p
ortant
— 4 —

Item Code No. Parts Name S
p
ecification Q'TY R
1
17 72270294 WASHER 745 Q436294A-1 1 C
18 10209118 WHEEL/HOUR 4323 RJQ527219-001V01 1 C
For the
p
rices and minimum order/su
pp
l
y
q
uantities of the above
p
arts, refer to the Parts Price List P.P.L.-645.
.
Notes: R - Rank
A: Im
p
ortant
C: Not Im
p
ortant
— 5 —

— 6 —
5. PRECAUTIONS FOR REPAIR: MODULE QW-4791
5-1. AC (ALL CLEAR) AND REMOVING OF MODULE
1. Perform AC (ALL CLEAR) when inserting a new battery, or else the memories and/ or counters
may give erratic displays.
Touch the AC contact and the main plate with the metallic tweezers.
The contact should be made for about two seconds.
2. On removing of the module from the case, please insert the precision screw driver between the
module and the case pointed by an arrows.
Note: After performing AC(ALL CLEAR), the mode is switched to the second hand and the indicator
hand home position adjustment mode at the home position adjustment mode.
Metallic tweezers
5-2. MEASURING CURRENT CONSUMPTION
This model starts correct positioning of the second hand in the H-SET mode immediately after AC.
When it is functioning, the value of consumption current would be a little higher as the internal circuit
operation would be different from the usual status.
To measure a correct consumption current value, operate as follows.
Hold down  and turn on the AC, and then let  go.
* After the operation above is finished, measure within one minute.
* Supply voltage is 1.5V.

— 7 —
5-3. ACCURACY CHECKING
1. Module confirmation mode
1) Press the  button in the Normal Timekeeping Mode to display the result of the signal receiv-
ing test.
2) In the Signal Receiving Test Result Mode, press the  button twice while holding down the 
button to display the version of the Accuracy Checking Mode.
3) The version is indicated with the second hand. Press the  button once to display the tens
place digit of the version; press it once more to display the units digits of the version.
QW-4791: “44”
2. Accuracy checking mode
1) Press  button at the module confirmation mode to enter the accuracy checking mode.
2) Second hand shows performing to test the rate of clock.
3) Press  button at the Accuracy checking mode to go back to the normal timekeeping mode.
B
B
A
A
B
B
Timekeeping Mode
Press A once, and th-
en press B twice while
holding down A.
TEST MODE
Accuracy Checking Mode
4 o'clock
position
4 o'clock
position
Indicated the last
receiving stationis Signal Receiving
Test Mode
* While displaying the reception result
in the test mode, press the A button.
Module confirmation Mode
(units digit)
Module confirmation Mode
(tens place digit)
Indicated with the
second hand.
B× 2

— 8 —
5-4. TIME CALIBRATION SIGNAL TEST MODE
1) In the Accuracy Checking Mode, press the  button twice to switch to the signal receiving standby
state.
(The last receiving station is indicated with the second hand.)
If the last receiving station is reset with the [All Clear] function, the station to first receive the signal
is indicated.
(JJY40:4sec, JJY60:6sec, WWVB:8sec, MSF:14sec, DCFF:16sec)
2) Press the  button to switch to the Signal Receiving Sensitivity Test Mode.
3) Press the  button to select the receiving station, and then press the  button to start receiving
the signal.
The second hand will move to the READY (33-second) position.
4) The result of the signal reception will be indicated after a while.
Signal recieving department The result of the signal reception
Success failure
JJY40 1 o’clock 11 o’clock
JJY60 2 o’clock 10 o’clock
WWVD 3 o’clock 9 o’clock
DCF77 4 o’clock 8 o’clock
MSF 5 o’clock 7 o’clock