GEKCO CLK056 Supplement

GEKCO
DIGITAL CLOCK
MODEL CLK056
ASSEMBLY & OPERATION MANUAL
GEKCO Inc.
1565 SW Cypress Ln
McMinnville, OR 97128
[phone] P/N 595-325 REV 181030
Copyright 2018
GEKCO Inc.
All Rights Reserved
Printed in the United States of America
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GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
GEKCO INC. Rev 1.0 1
TABLE OF CONTENTS
1. INTRODUCTION................................................................................................................................................ 3
2. OPERATIONAL SUMMARY.......................................................................................................................... 3
3. PARTS AND UNPACKING.............................................................................................................................. 4
3.1. TOP LEVELPARTS LIST ...................................................................................................................................... 4
3.2. DISPLAY BOARD PARTS LIST.............................................................................................................................. 5
3.3. MAIN BOARD PARTS LIST................................................................................................................................... 6
3.4. FINALASSEMBLY HARDWARE PARTS LIST....................................................................................................... 7
3.5. ENCLOSURE PARTS LIST..................................................................................................................................... 8
4. ASSEMBLY NOTES........................................................................................................................................... 9
4.1. TOOLS............................................................................................................................................................... 9
4.2. ASSEMBLY ...................................................................................................................................................... 9
4.3. SOLDERING..................................................................................................................................................... 9
5. STEP-BY-STEP ASSEMBLY .........................................................................................................................10
5.1. DISPLAY CIRCUIT BOARD.................................................................................................................................10
5.2. MAIN CIRCUIT BOARD......................................................................................................................................14
6. INITIAL TESTS.................................................................................................................................................16
7. FINAL TESTS....................................................................................................................................................17
8. IN CASE OF DIFFICULTY............................................................................................................................17
9. FINAL PCA ASSEMBLY................................................................................................................................17
10. FINAL ASSEMBLY......................................................................................................................................17
11. THEORY OF OPERATION.......................................................................................................................20
11.1. BLOCK DIAGRAM..............................................................................................................................................20
11.1. MAIN BOARD CIRCUIT DESCRIPTION...............................................................................................................20
11.2. DISPLAY BOARD CIRCUITDESCRIPTION.......................................................................................................... 21
12. FIRMWARE.................................................................................................................................................. 22
12.1. FLOW CHART ....................................................................................................................................................22
12.2. FIRMWARE DESIGN DESCRIPTION....................................................................................................................23
13. PCA PICTORIAL DIAGRAMS.................................................................................................................23
13.1. MAIN BOARD....................................................................................................................................................23
13.2. DISPLAY BOARD ...............................................................................................................................................24
14. SCHEMATIC MAIN BOARD.................................................................................................................... 26
15. SCHEMATIC DISPLAY BOARD.............................................................................................................27
16. DOCUMENT REVISION HISTORY........................................................................................................28

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
2 REV 1.0 GEKCO INC.
LIST OF FIGURES
FIGURE 1: DISPLAY BOARD TOP SIDE COMPLETED ASSEMBLY.......................................................................... 10
FIGURE 2: DISPLAY BOARD BOTTOM SIDE COMPLETED ASSEMBLY..................................................................10
FIGURE 3DISPLAY BOARD BOTTOM SIDE............................................................................................................ 11
FIGURE 4: DISPLAY BOARD TOP SIDE ASSEMBLY PICTORIAL.............................................................................12
FIGURE 5: MAIN BOARD COMPLETED ASSEMBLY...............................................................................................14
FIGURE 6MAIN BOARD TOP VIEW 1.................................................................................................................... 14
FIGURE 7: MAIN BOARD TOP VIEW2...................................................................................................................14
FIGURE 8: MAIN BOARD TOP VIEW3...................................................................................................................14
FIGURE 9: MAIN BOARD TOP VIEW4...................................................................................................................15
FIGURE 10: MAIN BOARD WITH STANDOFFS......................................................................................................... 15
FIGURE 11: MAIN AND DISPLAY BOARD INTERFACE CONNECTOR MOUNTING...................................................15
FIGURE 12 RTCMODULE ASSEMBLY..................................................................................................................17
FIGURE 13 ENCLOSURE BACK.............................................................................................................................. 18
FIGURE 14 ENCLOSURE BACK WITH TOP .............................................................................................................18
FIGURE 15 DISPLAY BOARD TOP SIDE ................................................................................................................. 24
FIGURE 16 DISPLAY BOARD BOTTOM SIDE..........................................................................................................25

CLK056
GEKCO INC. Rev 1.0 3
1. Introduction
The Digital Clock Model CLK056 was designed to fill the need for an accurate digital clock with the
capabilities of two time zone displays in a compact format.
This clock has 6 digits for hours, minutes and seconds and the hours display can alternate between
two time zones, i.e. Coordinated UniversalTime (UTC) and local time.
The CLK056 is offered in kit form or fully assembled and tested. The kit is veryeasy to assemble with
no surface mount parts.
This step bystep manual will guide you through the process to complete the assembly and testing of
the model CLK056 Digital Clock. The manual was designed so a total beginner in electronics can be
successful but the more experienced builder can skip anyunnecessary information. Also this design is
fully open source for both the hardware and firmware. There are full schematics and pictorial diagrams
of the hardware, also there are links and flowcharts of the firmware microcontroller code.
2. Operational Summary
The Model CLK056 has 6 digits of seven segment displays to displayHOURS, MINUTES and
SECONDS. The HOURS displaycan alternate between two time zones, which can be UTC and local
time. This function can be turned off bya menu selection if desired.
The six digit displayprovides Hours, Minutes andSeconds
Dual time zone display, alternates between two time zones every2 seconds, i.e. UTC and local
The display LEDs are high contrast red, 0.56 inch character height
Adjustable display brightness
Local hours can be set for 12 or 24 hour mode
Very accurate Real Time Clock (RTC) with battery backup
Powered bya U.L. listed 5 VDC wall adapter
Size: 4.16x 2.35 x 1.46 inches (Width x Height x Depth)
Weight: 0.30 pounds

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
4 REV 1.0 GEKCO INC.
3. Parts and Unpacking
The kit is packaged in the order that the assembly is recommended. Each assembly block has it’s
associated parts bag. Only open a parts bag when called for during assembly to avoid misplacing parts.
3.1. Top Level Parts List
Remove the parts from the main bag and separate each individual parts bags.
ITEM
QTY
PART NO.
DESCRIPTION
1
1
DBR656-KIT
Clock DisplayBoard PCA parts bag
2
1
CLK056M-KIT
Clock Main Board PCA parts bag
3
1
2217625
Real Time Clock (RTC) Module DS3231
4
1
CLK056HDW-KIT
Final Assembly Hardware
5
1
CLK0X6ENC-KIT
Enclosure Acrylic 6 Piece
6
1
54-660
AC to DC Power SupplyWall Adapter Single
Output 5 Volt 1 Amp 5 Watt 2.1mm Conn

DIGITAL CLOCK MODEL CLK056
GEKCO INC. Rev 1.0 5
3.2. Display Board Parts List
Clock 056 Display Board Printed Circuit Assembly (PCA) parts kit, P/N DBR656-KIT
ITEM
QTY
REFDES
PART NO.
DESCRIPTION
1
3
DS1,DS2,DS3
412-499
LED DisplayModule 7-Segment 2-Digit 0.56"
2
1
X1
434-3110
Socket IC Dip24-300
3
1
U1
442-3090
IC LED DisplayDriver MAX7219CNG
4
1
J1
131-1X10
Connector Header Single Row Male 10 pins
5
4
LED3,LED4,
LED5,LED6
412-125
LED Red PCB Mount T1 3/4
6
1
C2
26-102
Cap elect alum radial lead 10uF/16v
7
1
C1
20-104
Cap mono Cer 50v radial lead
8
1
R1
6-1002-12
Res metal film 1/4w 1% 10k
9
1
81-180911D
PCB DisplayBoard
1
2 3 8
6
5
7
4
3

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
6 REV 1.0 GEKCO INC.
3.3. Main Board Parts List
Clock 056 Main Board PCA parts kit, CLK056M-KIT
ITEM
QTY
REFDES
PART NO.
DESCRIPTION
VALUE
1
3
C4,C5,C6
20-104
Cap mono Cer 50v radial lead
0.1UF
2
2
C1,C2
21-220
Cap mono Cer COG radial
lead
22pF 100v
3
1
C3
26-102
Cap elect alum radial lead
10uF/16v
4
1
Y1
404-160
Crystal HC49
16.00 MHz
5
1
D1
55-62
Diode schottkyrectifier
1N5817-T
6
3
SW1,SW2,S
W3
64-1839
Switch Momentary SPST
7
1
SW4
64-1827
Switch Momentary5mm H
8
1
J4
131-1X10S
Conn Header Female Single
Row 10 pins
9
1
J2
131-1X06RA
Conn Header Right Angle
Male 1 row of 6
pins
10
1
J3
131-1X05RA
Connector Header Right Angle
Male 1 row of 5
pins
11
1
J1
134-002
Connector Power 2.1mm PCB
Mount
12
1
RN1
95-103
Res network 6 sip
10K 5 Res SIP
Package
13
1
X1
434-311
Socket IC
Dip28-300
14
1
U1
444-104-01
IC Microcontroller
Programmed
Part CLK056
V1.01
15
1
LS1
220-1420
Audio Piezo Transducer 30V
16
1
81-180912C
Printed Circuit Board
Main Board
1
2
3
4
5
6
7
8
9 10
11
12
13
14
15
16

DIGITAL CLOCK MODEL CLK056
GEKCO INC. Rev 1.0 7
3.4. Final Assembly Hardware Parts List
Clock 056 Final AssemblyHardware parts kit, P/N CLK056HDW-KIT
ITEM
QTY
PART NO.
DESCRIPTION
1
2
255-25511
Hardware Standoff Nylon M3 x 12 mm
2
4
255-29341
Hardware Screw Nylon M3 x 0.50 mm Thread,
6mm White (used for temporary assembly only)
3
2
255-29346
Hardware Screw Nylon M3 x 0.50 mm Thread,
16mm White
4
2
255-29347
Hardware Screw Nylon M3 x 0.50 mm Thread,
20mm Black
5
2
255-876
Hardware Spacer Round 0.25" Hole Size #4
21
4
3
5

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
8 REV 1.0 GEKCO INC.
3.5. Enclosure Parts List
Clock 056 Enclosure kit, P/N CLK0X6ENC-KIT
ITEM
QTY
PART NO.
DESCRIPTION
1
1
86-18111901
Front Panel Acrylic 3mm Transparent Red
2
1
86-18111902
Back Panel Acrylic 3mm Clear
3
1
86-18111903
Top Panel Acrylic 3mm Clear
4
1
86-18111904
Bottom Panel Acrylic 3mm Clear
5
1
86-18111905
Left Side Panel Acrylic 3mm Clear
6
1
86-18111906
Right Side Panel Acrylic 3mm Clear
7
1
86-18111907
Front Window Label
1
56
2
7
3
4

DIGITAL CLOCK MODEL CLK056
GEKCO INC. Rev 1.0 9
4. Assembly Notes
4.1. TOOLS
You will need these tools to assemble your kit.
Diagonal Cutters
Needle Nose Pliers
Flat Head Screwdriver
Philips Screwdriver (for the enclosure
only)
Pencil Soldering Iron (22 to 25
WATTS)
4.2. ASSEMBLY
1. Follow the instructions carefully. Read the
entire step before you perform each
operation.
2. Refer to the Pictorial and Detail Illustrations
for help in performing the assembly steps.
The illustrations are arranged in the proper
sequence, as called for in the assembly
steps.
3. Pictorials show the overall operation for a
group of assembly steps: Details generally
illustrate a single step. When you are
directed to refer to a certain Pictorial “for
the following steps,” continue using that
Pictorial until you are referred to another
Pictorial for another group of steps.
4. Position all parts as shown in the Pictorials.
5. Solder instructions are generally given only
at the end of a series of similar steps. You
may solder more often if you desire.
6. Each circuit part in an electronic kit has its
own reference designator (R3, C8, etc.).
Use these designators when you want to
identify the same part in the various
sections of the manual.
7. SAFETY WARNING: Avoid eye injury
when you cut off excessive lead
lengths. Wear safety glasses or
goggles and hold the leads so they
cannot fly toward your eyes.
4.3. SOLDERING
Soldering is one of the most important
operations you will perform while assembling
your kit. A good solder connection will form an
electrical connection between two parts such
as a component lead and a circuit board foil. A
bad solder connection could prevent an
otherwise well-assembled kit from operating
properly.
It is easy to make a good solder connection if
you followa few simple rules:
Use the right type of soldering iron. A 22 to 25-
watt pencil soldering iron with a 1/8” or 3/16”
chisel or pyramid tip works best.
Keep the soldering iron tip clean. Wipe it often
on a wet sponge or cloth: then apply solder to
the tip to give the entire tip a wet look. This
process is called tinning, and it will protect the
tip and enable you to make good connections.
When solder tends to “ball” or does not stick to
the tip, the tip needs to be cleaned and re-
tinned.
NOTE: What solder to use, leaded or lead
free? The printed circuit boards in this kit are
plated with lead free solder so if you choose to
use lead free solder the complete assembly will
be RoHS compliant. Regarding kits though, it is
more difficult to solder with lead free material
due to the higher melting temperature, so we
recommend using a rosin core, radio-type
solder (60/40) or (63/37) tin-lead content) for all
of the soldering in this kit. If you decide to use
leaded solder, be careful to wash your hands
after soldering and never eat, drink or smoke,
until you wash thoroughly and you are done
soldering. Contain all materials that touched
leaded solder in a special container dedicated
for that purpose. This waste can be disposed
of at electronic-recycling events or contact your
waste management company

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
10 REV 1.0 GEKCO INC.
5. Step-By-Step Assembly
5.1. Display Circuit Board
Figure 1: Display Board Top Side Completed Assembly
Figure 2: Display Board Bottom Side Completed Assembly

DIGITAL CLOCK MODEL CLK056
GEKCO INC. Rev 1.0 11
( ) Open the DisplayBoard Printed Circuit Assembly(PCA) parts kit, P/N DBR656-KIT
Refer to Figure 3 for the following steps.
Position the Display Circuit Board with the bottom side facing up as shown
U3
NOTCH
Figure 3 Display Board Bottom Side
Locate the 24 pin IC socket for U3
Place the socket on the board with the notch on the socket aligned with the notch noted on the printed
circuit board (PCB) silkscreen. Turn the board over and solder the corner pins and check to be sure the
socket is firmlyagainst the board and then solder the rest of the pins.
( ) X3: 24 pin DIP socket

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
12 REV 1.0 GEKCO INC.
Position the Display Circuit Board with the component side facing up as shown below
C1 R1 C2LED5 LED6
LED4
LED3
Figure 4: Display Board Top Side Assembly Pictorial
Install the decoupling capacitor.
( ) C1: 0.1 uF (104) radial-lead ceramic capacitor
( ) R1: 10 k(brn-blk-org-silver) resistor
NOTE: Before you install an electrolytic capacitor, look at it and identify the leads. One lead will have
either a negative ( ) mark or a positive ( ) mark near it on the side of the capacitor. The aluminum
electrolytic capacitor has the marking for a negative lead which may look like an oblong bar, sometimes
with a circle around it, inside an arrow. Be sure to install the positive lead in the positive-marked hole.
( ) C2: 10 uF radial-lead electrolytic aluminum capacitor (laydown the capacitor against the board
so it does not interfere with the enclosure)
C2 SIDE VIEW
( ) Solder the leads to the foiland cut off the excess lead lengths.

DIGITAL CLOCK MODEL CLK056
GEKCO INC. Rev 1.0 13
In the next step, make sure the LED displaymodules are oriented correctly. Match the decimal point on
the displaywith the orientation shown on the PCBsilkscreen. Solder the corner pins first and make sure
the displayis mounted flush with the board and oriented correctly and then solder the rest of the pins.
( ) DS1: 7 segment LED displaymodule
( ) DS2: 7 segment LED displaymodule
( ) DS3: 7 segment LED displaymodule
Make sure the LEDs are oriented correctly, there is a flat side on the LED housing or make sure the
long lead (anode) is inserted in the square hole and the short lead (cathode) in the round hole.
( ) LED3: LED Red PCB Mount
( ) LED4: LED Red PCB Mount
( ) LED5: LED Red PCB Mount
( ) LED6: LED Red PCB Mount
Note: LED1 and LED2 are not installed in this version of the displayboard.
( ) Solder the leads to the foil and cut off the excess lead lengths.
This completes the assembly of the Display Board. Connector J1 will be installed after the main board
assemblyis almost complete. Set aside for the final assemblylater.

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
14 REV 1.0 GEKCO INC.
5.2. Main Circuit Board
Figure 5: Main Board Completed Assembly
Figure 6 Main Board Top View 1
( ) C4: 0.1 uF (104) radial-lead ceramic
capacitor
( ) C5: 0.1 uF (104) radial-lead ceramic
capacitor
( ) C6: 0.1 uF (104) radial-lead ceramic
capacitor
Figure 7: Main Board Top View 2
( ) C1: 22 pF (22) radial-lead ceramic
capacitor
( ) C2: 22 pF (22) radial-lead ceramic
capacitor
In the next step be sure to observe the correct
polarity as noted before and lay the capacitor
down against the board.
C3 SIDE VIEW
( ) C3: 10 uF radial-lead electrolytic
aluminum capacitor
Figure 8: Main Board Top View 3
( ) Y1: Crystal HC49 16 MHz
For the next step, be careful to position the end
with the dot or line towards the “square pad”
and tapered outline on the circuit board. After
you solder the first pin make sure the pins are
fully seated in their holes, solder the rest of the
pins to the foil.
( ) RN1: 10 k103 resistor pack.
NOTE: When you install the diode, be sure to
orient the diode correctly. Always match the
band on the diode with the band mark on the
circuit board. The circuit will not work properlyif
a diode is installed backwards.
( ) D1: 1N5817 schottky diode
When installing the IC socket next, be sure to
align the notch on the socket with the notch on
the PCB silkscreen.
( ) X1: 28 pin DIP socket

DIGITAL CLOCK MODEL CLK056
GEKCO INC. Rev 1.0 15
Figure 9: Main Board Top View 4
( ) SW1: momentaryright angle switch
( ) SW2: momentaryright angle switch
( ) SW3: momentaryright angle switch
( ) SW4: momentaryswitch
( ) J2: Connector Header Male 6 pin right
angle mount
( ) J3: Connector Header Male 5 pin right
angle mount
In the next step, solder one pin and re-align the
connector if necessary and then solder the rest
of the pins. The connector needs to be aligned
with the silkscreen outline.
( ) J1: Connector Power 2.1 mm
( ) LS1: Audio Piezo Speaker
( ) Solder the leads to the foil and cut off
the excess lead lengths.
The next step is to install the mating
connectors between the display board (J1) and
the main board (J4). You will be temporarily
mounting the two boards together to make
sure the mating connectors align properly.
Open the final assembly hardware bag and get
the following parts:
Quantity2 of:
M3 x 12 mm nylon standoffs
Quantity4 of:
M3 x 6 mm nylon screws
The display board assembled earlier.
The display board connector
J1: Connector header male 10 pin
The main board connector
J4: Connector Header Female 10 pin
Refer to figure 10 and 11 for the next steps
Mount two M3 x 12 mm nylon standoffs with
two M3 x 6 mm nylon screws on the main
board as shown.
(2) M3x12
mm nylon
standoff
Figure 10: Main board with standoffs
Insert the 10 pin female connector into the
main board at J4.
Identify the gold plated pins on the display
board 10 pin male connector J1 and insert into
or mate with J4 the 10 pin female connector.
Place the display board onto the two M3 x 12
mm nylon standoffs, with the 10 pin male
connector J1 inserted into J1 on the display
board and insert two M3 x 6 mm nylon screws
as shown.
DISPLAY
BOARD
J1
MAIN
BOARD
J4
Figure 11: Main and Display board Interface connector
mounting
Solder the pins of the display board connector
J1 on the display board and then do the same
for the connector pins on the main board J4.

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
16 REV 1.0 GEKCO INC.
Now you can disassemble the two boards
together and set aside the two M3 x 12 mm
nylon standoffs to be used later. The four M3 x
6 mm nylon screws will not be used, if you plan
to use the acrylic enclosure, and can be
discarded.
J5 is not installed in this version of the kit.
This completes the assembly of the Main
board.
CIRCUIT BOARD CHECKOUT
Carefully inspect the circuit boards for the
following problems.
( ) Unsoldered connections
( ) Poor solder connections
( ) Solder bridges between foil patterns
( ) Protruding leads which could touch
together
Refer to the illustration where the parts were
installed as you make the following visual
checks.
( ) Diodes for the proper type and
positioning of the banded end
( ) Electrolytic capacitors for the correct
position of the positive ( ) or a negative ( )
marked ends
6. Initial Tests
Before installing the IC’s perform the following
tests.
DisplayBoard
Using a multi-meter to measure resistance
perform the following checks.
( ) Verify that the resistance with the
positive lead on C1 positive pin and negative
lead on C1 negative pin, is greater than 2k
ohms.
Main Board
( ) Verify that the resistance with the
positive lead on D1 cathode ( the component
end with the band) and negative lead on the
ground pad TP1, is greater than 2k ohms.
IC INSTALLATION.
NOTE: You will install the following IC’s on the
main circuit board.
CAUTION: Integrated circuits (IC’s) are
complex electrical devices that perform many
complicated operations in a circuit. These
devices can be damaged during installation.
Read all of the following information before you
install the IC’s.
Some of the IC’s you will install in the following
steps are MOS {metal oxide semiconductor)
devices. Be sure they do not get damaged by
static electricity. Once you remove the IC from
the foam pad, do not let go of it or lay it down
until it is in its socket. Install it as follows. Read
all of the following steps before you pick up an
IC.
1. Pick up the IC and touch the foam pad with
both hands.
2. Hold the foam pad with one hand and
remove the IC with the other hand.
3. Continue to hold the IC with the one hand
and straighten any bent pins with the other
hand.
4. The pins on the IC’s may be bent out at an
angle, and if this is the case, they will not
line up with the holes in the IC socket or
circuit board pads. Lay the IC down on its
side as and very carefully roll it toward the
pins to bend the lower pins into line. Then
turn the IC over and bend the pins on the
other side in the same manner. Do not try
to install and IC without first bending the
pins as described. To do so may damage
the IC pins or the socket, causing an
intermittent contact.
Install the IC on the display circuit board. Be
sure to line up the dimple with the circuit board
silkscreen

DIGITAL CLOCK MODEL CLK056
GEKCO INC. Rev 1.0 17
( ) U1: MAX7219 IC
Install the IC on the main circuit board:
( ) U1: ATMEGA328P IC
This completes theassembly.
7. Final Tests
Using a multi-meter to measure resistance
perform the following checks.
( ) Verify that the resistance with the
positive lead on U5 pin 20 and negative lead on
pin 10, is greater than 2k ohms.
( ) Connect the plug in transformer T1 to
power connector PS1 and plug into a wall
outlet and verify that the voltage with the
positive lead on U5 pin 20 and negative lead on
pin 10, is 5V.
8. In Case Of Difficulty
The “Visual Checks” that are provided below
will help you locate any difficulties that might
occur during the assembly and testing of your
Digital Clock. Additional “ In Case of Difficulty”
information is also provided in your Operation
Manual.
In an extreme case where you are unable to
resolve a difficulty, refer to the “Customer
Service” information at the back of the Manual.
VISUAL CHECKS
1. The majority of kits that fail are due to poor
solder connections. Therefore, you can
eliminate many difficulties by carefully
inspecting each connection to make sure it
is soldered as described in the solder
instructions section. Reheat any doubtful
connections.
2. Check the circuit board to be sure there
are no solder bridges between adjacent
connections.
3. Check capacitor values carefully. Be sure
the proper value part is installed at each
capacitor location and that the negative
( ) mark or a positive ( ) mark is
oriented correctly.
4. Check each resistor value carefully.
5. Be sure the correct diode is installed at
each location, and that the banded end is
positioned correctly.
6. Check the orientation and the correct part
number of the Integrated Circuits. Use the
pictorial diagrams as a reference.
9. Final PCA Assembly
( ) Locate the RTC module and install on
the clock main board as shown.
Figure 12 RTC Module Assembly
10. Final Assembly
Skip these steps if the enclosure is not used.
( ) Unpack the 6 piece enclosure which
includes a transparent red front piece, and
clear back, top, bottom and side panels.
( ) Remove the paper backing on all the
enclosure pieces.

GEKCO DIGITAL CLOCK P/N CLK056 ASSEMBLY & OPERATION MANUAL
18 REV 1.0 GEKCO INC.
( ) Locate the clear back panel and insert
two white screws into their respective mounting
holes and add two ¼” spacers. Lay this
assembly down on the work space with the
screw threads facing up.
Figure 13 Enclosure Back
( ) Insert the top panel of the enclosure
onto the main board assembly. Make sure the
switches properly align with the top piece of the
enclosure.
Figure 14 Enclosure Back with Top
( ) Add the main board assembly with the
top panel on to the screws and spacers.
( ) Insert the two M3 x 12mm hex
standoffs and secure to the two rear screws.
( ) Mate the display board to the main
board and make sure the connector in mated
properly.
( ) Add the left panel.
( ) Add the right panel and make sure the
hole is aligned with the power connect J1.
( ) Add the bottom panel.