Quoted from lowga:Fuse F116, a slow-blow 3 amp fuse is always blown. Replace it and the game functions normally again for awhile---then several games later, same problem again
I had this message on my machine not long before i sold it but mine wasn't blowing the F116 fuse though and turned out to be a loose wire to the 16 opto board. Your issue is different though and again must be a short somewhere to keep blowing the fuse. Not sure what that might be at the moment, i will need to have a look at a pdf of the manual again and see if i can spot something. I don't have the copy of the manual anymore, went with the machine when i sold it. F116 is effecting the flippers cause none of the opto's are working, pretty sure it is linked to all opto power being 12V secondary.
Edit* Found this and it may help solve your problem https://pinside.com/pinball/forum/topic/wd-keeps-blowing-12v-opto-fuse-f116
Eric can also most likely update you better with this issue.
I do have to add that i had several mods on my machine running off J116 and the one next door that also uses the 12V secondary supply. In well over a year i never had an issue from overtaxing the supply BUT having said that it may also depend on how long the machine is turned on for/played also. Perhaps my machine had already had the chips mentioned in the post changed before i got it, can't be sure about that.