Hello fellow Pinball fans. I recently purchased a Gottlieb Hollywood Heat and have been chasing down all the problems. Everything is now working EXCEPT it doesn't see ANY of the playfield switches in test mode. Therefore it won't start a game. Where should I look first? I have done the ground mod in the body, but not in the head. Also the slam switch bypass. Is there a tutorial or FAQ for everything to be done to a System 80B machine? A little background on me, I recently retired from over 40 years as an electronics tech. At one point I had a business repairing home arcade machines, but they were mostly EM's and early digitals, Flash, Gorgar, etc. Mostly Williams and Bally. I have virtually any piece of test gear you can think of, and have no problem doing board level repairs.

Tested with my Fluke 87. Z11 appears to be bad. I'm going to go ahead and replace all four. How do I prevent this from happening again?.

Thanks Pinsiders. Following your advice, I removed the 7404 Z11, and socketed a new one. The game now coins up and starts. This leaves just the usual driver replacement, contact cleaning, and adjustment, lamps, etc. I should mention that I purchased this as a non-working project game, so I have no idea when or how the damage was done.