So this Hot Shots is giving me fits and I'm reminded of why I don't like working on them.

So I am getting the Tilt Switch Closed error on the display on startup. This happens if A1-J5 and A1-J6 are plugged in or unplugged so that lends me to believe it's a board issue.

I have replaced Z11,Z12,Z13,Z14,Z15 - While they weren't all bad - I'm just in the shotgun approach now because I am out of options.

R19 checks good at 3k ohms.

U4 6532 PIA tested good on the Neo Lock Inquisitor, and I've changed out the 6502 processor. Although I get no activity on any of the lines. I'm assuming that's normal based it not completely booting? I'm not a Gottlieb guy.

Roms maybe?

Heck I'm out of ideas so any thoughts are appreciated.

Currently on a fossil hunting expedition with the kids but I'll post a pic when I get back. It's a brand new Swemmer.

The good thing about this expedition is that I brought the schematics to look at and it looks like the tilt switch goes through Z26 and then through into the RIOT at U5. I Bel eve the Swemmer layout as the original, which I still have.

Looks like I need to check R20 while I'm at it.

R20 checked out fine, Z26 was fine on the diode test but I'll change it out and see what happens. U5 RIOT tested fine. As it turns out Z26 has the Slam switch going through it, not the Tilt Switch.

PXL_20210313_230310943.MP (resized).jpgPXL_20210313_230353648 (resized).jpg

After unplugging A1j6 and A1J5 and removing Z13, Z14, Z15 and Z11 I still get the same Tilt Switch Closed. I should not have any feedback from the switches at this point so I wouldn't imagine I would still get the error.

Slam switch override is open and yes it used to work.

This one is self inflicted unfortunately. You know how Pinball 101 says don't work on anything live? You'd think I'd have learned that by now.

I was adjusting the pop bumper switch, not the coil , but score switch when it went. I'm assuming I sent some HV into the switch matrix but I have found anything really obvious yet. Just some questionable readings on chips.

Verified ROMS - They're good.

I also seem to remember reading something about the Qa transistor on the Swemmer boards causing this issue if it fails. I"ll have to go and see if I can pull that up.

Fixed it.

So I decided to go back over the chips and swap them, 1 by 1. The first IC i changed, Z14 (7400) and bloop it fires right up. The sequence of IC changes goes like this.

Chip 1 = On board when it died, Failed Diode test.
Chip 2 = Passed diode test, machine still didn't start.
Chip 3 = Passed diode test, machine started.
Reinstalled Chip 2 = Still passed diode test, machine didn't start.

Chips 2 and 3 are brand new but I guess it goes to show that even though testing good on diode works most of the time, it isn't 100%.

Thank you all for putting up with my long winded train of thought messages.