I am working on a HP55 that has a problem I was wondering if anyone has ever encountered. When you turn the calculator on, one particular LED segment lights up across the entire display.If you looked at the segments that make up the number "8", it would be the lower right segment that is lighting up for all digits. I switched out the calculator component board with one from another HP55 that I have, and the problem dissapeared, so there must be a fault in this board. Any insight anyone might have would be greatly appreciated.