Hello, I thought I would share some photos and a few details from when I installed a display backlight in my Micronta 22-195 Multimeter. I’ve used that meter for over thirty years and always wished it had a backlight. It was not easy, but I was determined to finish it. The plastic box that holds the LCD and the elastomeric connector was not designed to hold anything else. Especially not five or six layers consisting of a reflector sheet, two diffusers, a prism sheet, plastic lens, LED’s and a polarizer sheet. It took a little carving and sanding but I got it all sandwiched in there. To get the light to come through the display, I peeled off the silver reflective tape on the back of the meters LCD but left the polarizer. But before that, I pretty much ruined two calculators and an alarm clock to figure this out before trying it on the meters display. The six LEDs are driven by one AL5802 LED Driver powered from an LM317 with adjustable output which is powered by a 12V wall adaptor. All this is isolated from the meter with an optcoupler. Anyways, I wonder if anyone else has done this mod?
Update: Now that I have a 3D printer, I just printed a new holder for the LCD and the backlight but I forgot to take pictures.
I wish I would have owned a 3D printer sooner !