Tried all the suggestions, no chime, no image on screen, which is the old 23" HD Cinema. Have tried everything, with and without screen plugged in.

Waiting 8 hours, then finish this one below copied from post, and
then will post results, thanks.

- remove the CPU
- press the CUDA for 30 seconds or so
- remove the PRAM battery!
- unplug the power cable
- press the power button to discharge any left over power (this might not actually be necessary)
- let it sit with no PRAM battery for a while. I'm not sure exactly how long... probably an hour is good, but if you're patient, you∂ can leave it overnight.
- then put everything back together and try the upgrade again.