Introduction: Modded Casio F-91W
Hi everyone,
On this Instructables, I will explain how I manage to modde one of the most iconic watch ever made, the Casio F-91W.
I made 4 easy modifications on my F-91W :
- Change the plastic strap for a black nato
- Modify the color backlight, green light becomes blue
- Add a backlight LED
- Convert display with negative screen
Supplies
- 1x F-91W watch
- 1x 18mm Nato strap
- 1x LCD polarizer film
- 2x Blue 1206 LED
- 10cm of flying wire for PCB
Required tools :
- A cutter
- Some glue
- Watch repair tool kit
- A set of tweezers
Optional tools :
- A multimeter
- A soldering 3rd hand
- An old toothbrush and some Isopropylic Alcohol to clean the PCB
Step 1: Disassemble the Watch
This step is probably the most easy one :
- Remove the strap with the corresponding tool
- Unscrew the 4 bottom screws
- Remove the metal part and the seal
- Turn the watch case to remove the inner part
- Disassemble the battery holder and the screen
Now it's time to start modding.
Step 2: Negative Screen
Follow the steps below to transform a white screen to a black screen :
- Disassemble the screen and the connector from the plastic support
- Use the cutter to remove the initial polarizer film (Do not scratch the screen)
- Take your polarizer film and turn it in front of the screen to find the correct angle
- With your cutter, cut the film to the right dimension
- Stick your film to the screen (Try to avoid bubbles)
- Reassemble the screen and the connector in the plastic support
Step 3: LEDs Modifications
This step will convert your F-91W which has only one pale green led into a watch with two bright blue LEDs.
I know that the watch autonomy will decrease, but brights blues leds it's much more fun.
So let's start :
- With a soldering iron, remove the resistor closest to the LED
- Replace it with a piece of wire
- Remove the green LED and replace it with a blue one (Pay attention to the orientation of the LED)
- For the 2nd LED, carefully cut two PCB track with the cutter (See picture 4)
- Glue the LED
- Use the PCB pad to solder one side of the LED
- Use two flying wires to connect the two LEDs in parallel (Attention the bare copper must not touch any other component)
Step 4: Clean & Reassemble Everything
The last steps before wearing your watch.
- Clean the PCB with isopropylic alcohol with a Q-tip or an old toothbrush
- Assemble the white screen support with the PCB
- Put back the battery holder
- Replace the seal
- Close the watch case with the corresponding 4 screws
- Replace the strap
Step 5: Enjoy & Wear Your Modded Casio F-91W
To easily read the time, you have to get into the habit of orienting at the right angle your watch.
Despite this it's so cool to have a modded iconic watch on his wrist.
Have a nice day !