Matrix Orbital Corp

I am using LK204-25. It works fine for a few hours and then saturates to full contrast so is completely blank. At this point the contrast cannot be reset via the serial port and the only solution is to re-power.

If the display is started, data written and then the serial cable disconneted so that there is no longer any update, then the same behaviour is observed.

Any ideas and any further tests to diagnose the problem?

In top right-rand corner (assuming the DB9 is at the bottom) of the PCB is the contrast cct (it contains two resistors, a cap and a transistor)...can you check for a cold solder connection or evidence of inappropriate soldering...?