HP33 Display, contact corosion?

[teenix]

The minus sign could be a contact to the LED, or it could be the LED segment failed. The sign digit only has the "G" segment. The 2nd pin from the left side of the display is the connector.

Does the "B" segment light fully when looking from different angles, or still just partially. If partially, then it's possible that those segments are beginning to fail. If fully visible, then it could be the little wire connectors inside the device that connect the LEDs to the circuit board, although this would be odd as they are quite small.

Problems can arise from poor connections from the CPU as well. It the back case is removed and the calculator can be powered up, putting minor pressure around the frame that supports the ICs might confirm this.

cheers

Tony