Hey all! Just got my first pin, a Hollywood Heat that I'm sure I overpaid for (I missed one on craigslist for $600 a year ago and beat myself up, so I felt compelled to drop $1400 on this one)

Overall in pretty good shape, with at least two previous owners who did some modding on it-- a bad ground mod, a good ground mod, replacement MPU, leds, freeplay set up in the weirdest manner I've seen (hold the right front button and press start to add a credit? why not just tie it to one or the other?)

I'm doing my best to go through tons of topics and articles and wikis on 80Bs and look at all the normal maintenance and updates and such, as well as plenty of time spent reading about general troubleshooting. However, I'm not sure where to go from where I'm at right now.

There's at least one dead coil in the pf, which is fine, whatever, will replace later (it's one of the multiball kickouts) The others all work fine, except that 8-9/10 times, any of the four slingshots being hit will reset the game. Reset is maybe the wrong word here-- it game overs the current play session, plays the end of game music, etc. If I just tap lightly on one of the two slingshot switches, it'll fire, but any serious contact with the rubbers will, well, see for yourself:
edit: clarification, the pop bumper does not do this, just the slingshots

Since the switches for the slingshots work, and the solenoids fire, and it appears everything is correctly grounded, I'm not totally sure where to go from here, or what I should even start probing at.

And while I have you here-- the transformer has a power outlet built-in, which is rad if I decide to add undercabinet lighting or something down the road, but my outlet tester says it has hot and neutral reversed which... is not what I would expect unless a previous owner popped open the transformer and rewired it, though maybe that's expected?

Continuing to pore over schematics and youtube and wikis

The pop bumper works fine and is on the same 24v as the slingshots, which means the PBCB wouldn't be the culprit (only proposed because it's where the 24v would potentially touch 5v)
Resistance across the top right coil (because it's easy to probe and poke) is reading >3ohms, so that should be fine

If the entire system was rebooting it would sort of make sense to me that it was the coils dropping too much voltage, but it just... ends the game. Records the high score even, though it skips the process of counting the multiball bonus and taking initials. Aaaaand if I only delicately touch the switches, it'll play sounds and add points. It's only on a solid hit on the slingshots that it does this, and I can't figure out any avenue to investigate from here

Could it just be the logic board shitting out trying to add points or something???
Actually, following the schematics, how does the MPU recognize that a slingshot got hit to add points?

Figured out that they're not CPU controlled, which is why I'm confused about scoring-- can't identify any secondary wires or switches that are tied to anything for scoring, though I can see it add points and make sounds when it hits, so I know that it does. Gonna poke my head back in there with a keener eye, I guess.

Waiting on a shipment of parts that includes new diodes, but it's odd that it would be all four slingshots and only the slingshots that are causing the problem, no?

Slam switch is completely disconnected, so that's not it-- though I did experience some weird behavior with opening the coin door causing problems that I can no longer replicate, writing that off for now

However, some investigation with a chopstick revealed a potential suspect?

Pop bumper and flippers wouldn't have leaf switches, which sort of explains why it's only the slingshots

Also discovered that at least two of the solenoid leaf switches are completely dead, and one is broken off so it'll never get caught by the rubber. Guess I'm adding those to my shopping list.

Slam switch inside the coin door has its two wires soldered, so that guy should be permanently closed, though TBH I haven't probed it, based on that assumption. If there's a second slam switch, I'm not seeing it anywhere. (there is a tilt switch under drain, though that's def not the issue)

Didn't even notice that score switch in the top left, but I can poke the score switches a hundred times with 0 issues, so I think that rules that out.

Switch 32, which appears to be operating correctly, based on my pokes and the switch test in test mode (took me a while to find that switch in the manual last night as well, don't worry)

Doubtful it's related, but I also just noticed the pop bumper doesn't score points, which I guess means a bad 5v, but rather than mucking with the 30 year old board I just ordered a replacement for that

Kneed the coin door, pounded on the playfield, nothing happened (though I did manage to trigger a slingshot score)

Also just noticed that the A12J1 connector is effectively snipped off, and I can't figure out where on the MPU that's supposed to connect to down the line

edit:
this supplies the 24v to the playfield
which means that.... that 24v is coming from somewhere else now, I guess

While I'm at it, what is this "Q" on the switch at the top supposed to mean?
edit: oh, that's some switch from the mpu controlling when the coils have 24v running to them when a game starts, innit?
hh_coils (resized).PNG

Makes sense, thanks

That A12J1 is not connected is a bit weared. Do the slingshots react when you are not in play, normally they shouldn't

Figured this one out, or at least a reasonable narrative-- two owners ago dude did a really shite ground mod. Took allllllll of the grounds, twisted them into a big rats nest, and used about 50ml of solder to just paste them all to the transformer. (owner I got it from undid that and did a proper ground mod)
The wires that run into A12J1 have just been spliced to the wires from the other side of the connector-- so I think he just went crazy snipping every connector for the ground mod and then realized he goofed on that. The two 27v AC lines aren't spliced, but it looks like those don't actually get used for anything on the other side of the connector, so I think that should be "fine"

For the slam switch ( there is only one) you should check if it is closed for the MPU, meanning you have groundlevel at MPU A1J5P10

Confirmed the slam switch wired are grounded

Could be also a bad connection at A1J5 edge connector.
I recommend to replace contacts at MPU J5 & J6 as they are VERY OFTEN the cause for problems in Gottlieb games!!!!!
Makes no sense to do further testing with the switches if you are not sure that these contacts are 100% OK!

The MPU is a replacement Swemmer board so the contacts on the board side should be good, but I'll look at messing with the connector

e: browsing around for info on Swemmers said other people had some weird slam tilt issues with them
curious.

Okay alright okay alright!!

Traced out the slam switch, went all the way to whatever wiring harness has all the coin door mechs
Accidentally triggered the right coin switch. "Oh right, I guess those would still be connected even if it's free play"
Notice that the left coin switch has the spade connector on the wrong terminal. "Oh huh, guess I'll fix that while I'm down here"
Notice that occasionally when I trigger the left coin mech, it pops into test mode. But only sometimes. I swing the door around, jiggle the wires to everything, can't reliably reproduce.
Disconnect the harness, power cycle the machine, won't start because the slam switch is open. Makes sense.
Reconnect, power cycle, disconnect. Game does not complain about slam switch.
Game plays fine.
Noticed if I manually hammer on the slingshots the music will cut out, but was not able to reproduce during a game.

Have not figured out what is going on in the coin door or what wire I need to replace or what short I need to fix but
I have traded a large problem for a small problem, and the game is now actually playable