Update.
Got the board back today. It now will complete a calibration (no more cannot detect cable so you can't proceed) But it fails CH1 trigger and vertical. Cannot get any kind of a decent trace on the screen...
Further testing shows that there's a solder short on pin 20 to the large GND pad, see pictures.
Checked it in four wire REL mode on my Keithley 2000, it's 60uOhms, so it's definitely between the pin 20 pad and the GND plane (no way can it be the chip or at the other end of the trace).
The pad can be seen on the donor board.
It looks like it's going to be heading back to NYC
Question: Will performing the operation twice increase the likelihood of killing the chip? In other words are the heating effects cumulative?