Since posting, I re-checked all the fuse clips. It seems that F1 and F2 on the power supply board are really loose and about to totally snap off. They are not gripping the fuses tightly. Looks like this will be the next fix on Rocky & Bullwinkle...the saga continues.
First point of action on DE machines - replace the fuse clips on all boards. Get rid of strange problems like these !
+1 on this tip. there is not one data east pin around that i have seen with good original fuse holders.