Replaced the worst 2 pots with fairly stable minimum few 100s of ohms
settings of the rest, no LEDs.
I'm now assuming the inbuilt flash memory of the
P89LPC936F is corrupted as distinct from the RAMs. There is a vacant
header for in-cct programming with RST on the overlay. This line goes
to the INV-RST pin of the uC and according to the datasheet a LOW on
there will reset the uC, but no change still no LEDs. It looks as though
to erase the flash , needs a Chip Erase command via in-cct programming,
so that looks like the end of this usual digital farting about. One more
effort ,Cannot find "factory reset" for Line6 spider stuff, will try 5
seconds on each at power-up and then 2/3/4 of the adjascent ones.