The 1995 Seiko Super Runner was my first digital watch. The blue electroluminescent backlight lit up the numbers instead of the background. It cost about $140. The grey painted case scratched easily and quickly became disreputable. After 2 replacements, I thought "I have to find a cheaper watch."
The Casio F91W was on nearly every top 10 list. This is surprising considering the watch has a small face, looks cheap, and the backlight barely illuminates the first digit. Maybe I was missing something here. With little to lose I bought the F105W illuminator at the drugstore. It looks the same as the F91W but has a vastly improved Timex indiglo style blue backlight. I put the watch on and was underwhelmed. It looked cheap and the small display was hard to read. 30 minutes later I took it off and went back to an analog field watch. I immediately knew there was no going back to an analog watch. The digital watch with its affordability, light weight, alarms, day of the week, and backlight had become indispensable. I put the Casio F105W back on and never took it off again. It is a masterpiece.
A note about style. Many articles say the F91W is supposed to be for hipsters and terrorists and people that are trying to make the statement that this watch is for people that don’t like watches. Let me address some of this. First of all I am not even sure what a hipster is. Second, I DO NOT WANT TO KILL ANYTHING. There is too much death and destruction in this world. Third, I don’t know anything about fashion. As beautiful as these watches are, I cannot see myself walking around with a $4500 Bell and Ross. The F91 is about function. Lightweight, backlit, alarms, and day of the week. If people want to call me a hipster doofus for wearing this watch, well they are probably right.
Casio announced a new version F91WM-3AEF with an olive green body. I liked the color and bought one knowing the backlight would be totally inadequate. The backlight was totally inadequate. But the F91W was slightly smaller and lighter than the F105. It felt like a little sports car. It is my favorite watch and I rarely take it off. But there was a problem. The backlight was not bright enough.
I had to figure out a way to fix the backlight.
The backlight is located on the left side of the display and points straight up into the back of the bezel instead of shining directly into the display. There were a few crazy ideas: plastic light guides, tiny 45° mirrors, tin foil reflectors. That left only one way. The LED had to point directly into the LCD display. Maybe this you tube video would work.
Walmart had 3 gold F91s for $7 each to test the backlight modifications. This would become a critical piece of the puzzle. I removed the freaking tiny 805 SMD LED and re-soldered it at a 45° angle trying to shine it into the side slot of the LCD display. It worked. Now the entire display was lit up.
Then I tried the modification on my favorite olive green F91WM-3AEF. It didn’t work. The backlight was still dim. I re-soldered the LED at every possible angle 45°, 90°, 60°, 25°. Nothing worked and I was ready to give up and go back to the F105W. Wait a minute, if it worked on the gold F91W why didn’t it work on the olive green one? The LCD on the gold model has a slightly green/yellow tinted background to match the case, while the olive one had a light grey background. The LCDs were different and the backlight modification worked on the gold display but not on the light grey ones. This is probably due to different LCD mirrored film and backing layers. The next bit was easy. Install the modified gold module into the olive green body. The LCD green tint, with the green LED, and the improved backlight make this one cool watch.
dave@worldsworstwriter.org 2024-10-10