Let’s start with the switch test. Do any switches report multiple closures when activated?
https://www.pinwiki.com/wiki/index.php?title=Gottlieb_System_80#Switch_problems

hey there - can't believe i found this thread, I must have inadvertently bought your broken hollywood heat from the dealer you sold it to.. he told me he had just shopped it and unfortunately i didnt play it long enough to figure out that it had this catastrophic issue.
YeOldPinPlayer: he said he just replaced the MPU and as far as I can tell its brand new.. youre recommending a switch test to rule out that theres nothing wrong with the MPU circuitry but this a brand new MPU what could be wrong with it?
Trying to follow the instructions you linked to but its so technical I can't even figure out what to do.. "Using a short length of wire, short each column drive to each row return, one at a time" huh? and then "A single switch closure should be shown as each connection is made." shown where? on the alphanumeric display?
The test is a little complicated is there a video someone can link of someone doing this test so that I can follow it?

Raidersshane2: Question, did you replace the MPU to try and fix this issue or did you replace it for another reason? You said the technician worked on the bumper bay and left it messed up. Well was it working in between replacing the MPU and the technician looking at it? Trying to rule out if its the MPU without having to go through this switch test and if the tech messed it up working on it almost sounds like maybe he cut a wire or something.

I just took these photos because I was about to start a new thread before I saw this one. I see theyre a little blurry so I'll get some more. Any input from any of you pinball geniuses would be super appreciative!!

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If your switches have a diode that has failed or a shorted leaf you can get phantom or wrong switch closures.
There is a YouTube video on switch matrix testing:

and

great videos but too complicated for me :O i dont have an electrical background so unfortunately they're over my head so I dont trust my ability to find the offending diode.

Question: could I just replace or refurbish that whole drop target assembly? Once I disconnect the harness for the assembly the game works fine, minus the drop targets of course

i took some more photos of the switches on the drop target assembly. the last target in the line up sticks on the playfield takes a couple hits to knock it down i wonder if that might be part of the problem

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quantumjosh You need to get to know some local pinheads and have them get you started. Try posting in this thread and asking if anyone knows anyone near you: https://pinside.com/pinball/forum/topic/machines-on-location-in-philadelphia

Yes but unless you find out what the problem is you won't know if that will solve it or not.

A buddy could walk you through the test process and get you started in a few minutes.

So I pulled out the drop target assembly and snapped this photo - there is a wire missing here right?? its not supposed to be just the first two linked? assuming thats my issue what next? where can I get that little insulated piece of wire? I have a soldering iron already

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nevermind that was not the answer.. checked the top target and its the same. ill ask around locally thanks