LCD Without Wire Connectors

I have a Radio Shack count-up/count-down timer, catalog #63-878. It's about 2.5"x3.2"x0.70" thick.

It's around 10 years old and some of the input keys had become sticky.

I had to remove the back, then remove the circuit board which was held in by four screws.

As I gingerly removed the circuit board, the LCD display just fell off the circuit board. I cleaned some liquidy gunk from the circuit board and the rubber-membrane keys, and re-assembled the timer.

The display has what looks like a rubber strip on the bottom edge which contacts about 12 gold plated pads on the circuit board. The contacts are just lying flat on the circuit board - they are not edge connectors.

The four screws that hold the circuit board to the case also seem to make the circuit board press tightly against the rubber strip on the bottom of the LCD.

After re-assembly, the timer works.

I'm glad it didn't have a ribbon cable because they seem to be so fragile.

BUT.. how is contact made from the circuit board to that LCD?

--- Joe

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That rubber strip has a lot of conductive strands that make contact with the gold pads on the circuit board and the contacts on the edge of the LCD display.

Visually, think of it like a strip of corrugated cardboard on edge with little bits of wire in each corrugation. ;-)


Reply to
Jeffrey Angus

It's known as zebra strip. It's a sandwich of hundreds of tiny regular rubber strips, alternated with hundreds of conductive rubber strips. Compared to the sizes of the gold-plated print lozenges that form the connection points, and the spaces between them, several conductive strips will lie on each lozenge, and at least a couple of regular rubber insulating strips, will be in the gaps. When the whole caboosh is tightly fixed together, the conductive strips join the PCB lozenges to the deposited metal connections on the LCD glass.

Have a look at

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Reply to
Arfa Daily


It's that rubber.

It's made of of axially stacked layers of conductive and non-conductive elastomer. google "zebra strip" for more info.

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Reply to
Jasen Betts

Thanks for the helpful info, folks. I had never heard of a "zebra strip" and with my eyes there was no visible indication of conductively separated segments on that rubber strip.

--- Joe

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