Apple ][ europlus PAL card issue.

Hi All from this Oz Apple II owner.

I've just got my first Apple II. It's a Europlus, with the Language card in slot 0, an I/O disk card in slot 6 and a PAL card in slot 7.

I've got the disk drives working (Had to make a 19 to 25 pin adapter as that had gone missing) and I've fixed the bootup garbage issues it had (It was the 6502 of all things! I popped it out of the socket while looking around for faults and the pins were black. Some Deoxit and a hard eraser fixed it up a treat) but my Google-Fu is failing me with the final issue.

On bootup, the display (on a colour screen) is not right. Most of the time it boots to a deep emerald green. Sometimes to Blue. Once to washed out white. Occasionally to black.

I assume there's an issue with the PAL card, but I'm not sure where to start on it. Does anyone have any resources they could point me to to start working on this? My technical level is "intermediate" insomuch as I can test logic levels, and continuity, but I don't have a Osciliscope or any more advanced skills.

Cheers!

John "Cheshire Noir" Parker.