Fitted a 100uF cap to the Composite out on the VDU card as I noticed a tingling touching the video lead (always noticed the same with the PSU as well) - video still works fine and thought I had beaten the funny voltages....
Refitted the 8154 and they were gone, then they came back...
Well I spent quite a bit of time before my virtual people / real beers Thursday evening, de-soldering (well destroying with a rework heater and extracting each pin) my nice red socket as I thought I had an intermittent ground connection for the 8154 which could explain the odd 7v on SIN and SENSEB if a chip was being powered through unusual pins - and flexing the 8154 seemed to reduce it to 5v - got a similar effect with my eliminator board.
Wow was that hard to get out thought I had cleaned the holes and decided to put a nice turned pin - got that trapped half way in as some holes were not quite clear and had to break it to take it back out - now fitted a standard socket and the fault is back but flexing the chip in that area has the same effect. So I thought.
Use the scope to look at the lines - nothing - meter also shows normal things - hmmm - difference my scope has a good ground... chasing ghosts again...
Thinking about it flexing the chip near there I could have touched pin 20 (GND)
I can only think it is to do with ground as if I touch the shield on the Composite the voltages drop the same way.... This is analogue stuff, like TV, radios and things.... not my wheelhouse....
Anyway as with my SCRUMPI - hook the ground clip from the scope to the board and all is normal... except I have lost my nice red socket and burned my fingers...