TS-940 LCD Display LED Installation and Clock Battery
Replacement
6. Once you have the display detached from the clock board, lay it down
with the display down and the circuit board facing up. Use a small
pencil type iron to remove the 2 existing incandescent light bulbs
from the circuit board side of the display. There are 2 small pads on
each end of the display. Simply heat each pad very quickly and lift
up the wires from the light bulbs. You can also choose to just cut
the wires on the bulb and lift them out. Pull straight up on the light
bulbs and they will come right out.
7. To install the new LEDs, bend the – side (Short wire) at a 90
degree angle and cut it to about ¼” as shown. Then, solder one
side of the 510 ohm resistor to the + side of the LED as shown.
8. Next,
just insert the LED into the space where the old lights came out
and solder as shown. NOTE: Pay attention to which side is + and -.
They are mounted in different directions on the board as you can
see so make sure that you have the polarities correct. Once you
have the LEDS correctly mounted on the LCD display, re-mount
the LCD to the clock board using the 4 screws that were removed
in step 4.
9. Be sure to plug in the 2 conductor cable that was removed in step 4 and
the 10 pin connector from Step 5.
10. Remount the LCD Display and Clock module using the 2 screws that were
removed in Step 3. It is a good idea to test the display to make sure the
LEDs were installed correctly. The LCD display should have a great
looking Blue color with nice high brightness!
Clock Battery replacement
While you have the front panel of the TS-940 tilted out, it is a great time to remove
and replace the clock battery. This is a 3V memory retention battery for the
clock/timer that will provide years of service, but one that rarely gets replaced.
Here is how:
1. Look at the existing battery and its orientation. The positive side (+) is on
the top normally. On most batteries, it is clearly marked.
2. It is a good idea to check the voltage across the battery with the power
unplugged from the radio. If it is +3V or above, the battery is still good.
3. To replace the battery, simply unsolder both sides of the battery and
remove it. Re-solder the new battery making sure that the + and –
terminals are oriented correctly.
4. NOTE: Some TS-940s have 2 batteries soldered into the clock module.
You can replace these with one. The 2 batteries were apparently an
optional way of extending the battery life but to our knowledge, there was
no other reason since they were in parallel.
5. After the replacement is finished, you can carefully tilt the front panel back
into place and re-install the 2 flat head screws that were removed in Step
2.
6. Replace the top and bottom covers.
