[SOLVED] kernel-6.1.65 crashing

Slack64-current fully updated. I have been using the stable kernel 6.1.6x versions (huge config) and they have been rock solid. When I upgraded from 6.1.63 to 6.1.64 my system started suddenly stopping (turned completely off - black screen, no fans or anything). I checked my .config file with the one issued in the official release and found differences so I rebuilt 6.1.64 with the proper .config file and it is rock solid. Problems started with 6.1.65. The .config file is the official 6.1.65 .config file but the sudden turning off is now worse. Occasionally it will reboot but usually suddenly turns completely off. Can't spot anything in log files (/var/log,messages or dmesg) at all to offer a clue to the problem.
Move back to 6.1.64 and everything is perfectly stable. Haven't found anything similar in searching. Any ideas or where to look???