After the last post, did some basic testing of the two A/B cards. One just purchased was an unknown, the other purchased from ATY many years ago. It was put to bed sometime back, well packed. On first attempt, didn't get anything out. Clock patch did have a few fixes to make. Switched to the new one, booted fine. Went back to the original, no joy. A few sessions later, reseated CPU, no joy. Replaced the CPU, fired up.
Never had a CPU fail, this one only over clocked by 10%, worked when stored.
Something else to put on the trouble shooting list.
So far, removed the Nemesis, waiting for RF shielded coax in the post, will test with exxos buffer before testing with 889VL6 config.