HP48S strange behavior

[Brad Barton]

(06-28-2019 05:03 PM)BartDB Wrote:  Underneath is a grey sponge strip that pushes it onto the main PCB. This sponge deteriorates and causes a bad connection. It is best to replace the sponge strip it while you can.

What is a good material to use to replace the sponge strip> I've tried a few different pieces of foam I've had lying around, but none see just right. Any pointers on the best foam to use?

Brad