29 October 2017

Failing old LCD displays

Following my recent interest in old numeric display technologies I came across old calculators, and started collecting them. In early 1970's there was a lot going on in the research of display technologies, so while Nixies were fading out, VFDs taking their place where there could be a lot of environmental light, LEDs and LCDs were entering the market.

Overheating causes early LED displays to fail faster, especially if run at full brightness.

Sharp EL-5103S
Early LCDs on the other hand lost the "vacuum" inside and became unusable. You can see the failure as a darkened area in the corners/border and there's nothing you can do.

But I wouldn't expect this kind of failure from my Sharp calculator made in late 1980's or the VHF transceiver of early 1990's! Unfortunately replacing an LCD is not easy and you can hardly fit a replacement in the same space. So these devices just turned into (my personal) museum pieces.

The upper area of the display shows signs of air leak.

Too bad for the scientific calculator that served me in high school and at the university. But it looks like a modern replacement costs less than 10€! And I will look for some old battery powered pocket calculator as well, possibly with LED display.