As with the 1944 board, this came from the same seller with the same fault of a solid blue screen.

and like the 1944 board also was that the battery still had 3.6v present, the difference being was that the CPS2 suicide test EPROM didnt work with this indicating that the decryption code was still present in the memory. It is possible for the decryption code to get corrupt and with no other signs of fault I took the plunge and removed the battery, this time thought I discharged the capacitor next to the battery to make certain that the RAM with the decryption code in lost all power. The suicide test EPROM now worked.
After burning 5 new 27C4096 EPROMs for sockets 3 to 7 I fired it up and all is well again.