Hi Glyn and SB.
Re the Philips "A4" thing - I thought you'd like that.
And regarding the TBA chip. that would have been an excellent suggestion but for the fact that it was the original device fitted to the set.
Tim J. (Studio 263) of this forum had an interesting suggestion re the sync separator triggering on the burst rather than the sync pulse so a check of the video DC levels into the chip may reveal something.
Regarding DC in the scan coils, the raster itself is correctly centred, SB, it's just the picture within the raster. I think they used to call it "False Line Lock" in old books.
Thanks all.
Kind regards.
From Mike.