SCTV Clock Assembly Manual
1/24/22
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Step by step guide
Since the clock has a transparent case, the effort you put into making sure that all the parts are installed
neatly will be reflected every time you or someone else looks at the clock. For this reason, it is
recommended that you take your time to ensure that every part is straight before soldering the second
pin. You can reheat a pin and move the part with your fingers to align it properly. This is the method
used for the factory-assembled clocks.
0) Check that the surface-mount part U8 is not installed. If it is installed, then remove it by heating the
side with two legs using a blob of solder, then prying it up a bit. Heat the leg on the other side and pry it
up a bit. Repeat until the part is off the board. Remove the excess solder so that the pads are mot shorted
together.
1 and 2) Install the small round battery contact in the center of the B1 footprint, then install the large
battery holder on top of it, with the open side facing the edge of the PC board. Solder them both.
3) Install and solder the P6KE18A diode D3 next. Bend the legs to a 90-degree angle first. Install the
diode with its striped end over the stripe shown on the board. Bend the legs apart at a 30-degree angle to
hold it in place while you solder it. Trim the excess leads with diagonal cutters.
4) Install the USB jack J9. Snap it into place, then be sure that it is straight instead of tilted. Solder one
of the big tabs first. Check that it’s still straight. Reheat and straighten it if not. Then solder the other big
tab and the four small pins.
5-6) Install the 500K trim pot R1 (marked 504) and the 10K trim pots R2 and R3 (marked 103). Spread
the legs on each of these pots after installing. Solder the center pin of each pot, then reheat this pin while
pressing the pot against the board, to ensure that it fits tightly against the board. Check also for square
alignment to the board to keep a neat appearance. After they are aligned, solder the remaining pins. Trim
the excess lead length.
7) Install and solder the long socket strips for U2 next. Place both strips in the board, turn it over and
solder one pin in the center of each strip. Then turn the board over and make sure that the strips are
straight. Then solder the remaining pins.
8) Install and solder the short socket strip in the middle of the U2 footprint. Again, solder one pin first,
make sure it’s straight, then solder the remaining pins.
9) Install the DC power jack J1. Solder the center pin, then reheat it and align the block so that it is
square and flush. Solder the other two pins.
10-11) Install the two small headers J3 and J5. Be sure that the plastic tab is towards the center of the
board. Solder one pin on each then check that they are fully seated. Reheat that pin while pressing down
on the header if needed to make it flush with the board. Solder the remaining pins.
12) Install and solder the MPSW42 transistors Q2-Q5 next. Cut them from the tape strip with the leads
as long as possible. Be sure to orient these parts with the flat side as shown on the board. Spread the
outer legs 30 degrees to hold them in place while soldering. Check and adjust the parts’ alignment after
soldering the center pin of each before finishing the soldering work. Trim the excess lead length.
13-14) Install the two large headers J2 and J4. Be sure that the plastic tab is towards the center of the
board. Solder one pin on each then check that they are fully seated. Solder the remaining pins.
15) Install and solder the 1uF electrolytic capacitors C29 and C30 next. Observe polarity! Note that the
Japanese manufacturers mark the negative lead of the electrolytic capacitors, but the PC board marks the
