Cyclone / sys 11 display issue... need to call in the big guns.

The top segment ("A" segment) on the two bottom (numeric) displays was out. There was some burn on the display as well so I decided to replace it with a new LED display. When I put the LED display in it appeared to be all good, but after about 5 minutes the "A" segment faded out to nothing. This is a repeatable behavior. If the MPU cools down the segment will be on but slightly dimmer than the rest and eventually go out all together. Here's what I've done so far:

Reflowed all solder joints, tried re-seating related IDC connectors. Replaced U41 PIA. Didnt have replacement SIP resistors so I switched #2 and #5, same result. Tried new ribbon cable between mpu and display. Didnt have a replacement connector for the display so I de-soldered it and flipped it upside down and still have the same result. What am I missing / forgetting? Thanks in advance!

Turned out to be PIA at u51. More like PI*T*A 51 am I rite?