Intro: Smart Tag Hardware Upgrade: LCD Backlight
The original Smart TAG (Malaysia) comes with a LCD without backlight, it is incontinent to check card balance under low ambiance light condition. I saw my friend BP Tan modified one unit to get the backlight on, he had happily taught me and gave me some LEDs for modification. See simple steps as below.
Tools / parts required:
- T10 screw driver
- Soldering iron
- Super glue
- LED x 2
Remove small screw cap and battery cover, then remove two T10 screws as indicated.
- Remove LCD cover.
- Solder 2 LEDs in series together with a 470 ohm chip resistor. The resistor value can be tailored to get a desired brightness.
- Bound LEDs and chip resistor on both side of LCD by using super glue.
- Connect LED terminals to PCB.
- Anode and cathode location as indicated, the original cathode location was on one of buzzer terminal, however, I've moved it to battery negative.
- Some foam and dark color marker pen can be used to mask out undesired light leaking.
- Reassembly the unit, now the Smart TAG with backlight is ready to use.
- The elegance of this modification is the light will be turned off automatically in standby mode.