If you can, please identify exactly which number IC pin (or marked up photo please) that white wire once connected on UG6, and also if that wire was a single conductor or a really skinny shielded conductor. Judging from the number of pins on that connector, it not only had DC power, but also access to video, vertical, and horizontal sweep pulse information. That UG6 chip is a video display related PAL and the wire could be bringing out the pixel clock, or other frame sync information that could be useful for external frame capture, mirrored display or scan conversion purposes.