I don't know about your replacement component compatibility, you'll need to do some research there. If they are OK replacements, break your problem down into smaller sections. Take the "K" lights, and get them working properly, then "I", etc. Only replace an "upstream" component if it proves to be bad, and this might correct other failures.

Let me download the manual and take a look...

Wait...first, what happens with the K-I-S-S letters when you go Lamp Test?

Do you have a logic probe, or at least a Digital Multi Meter?

Yeah, a logic probe is priceless when owning solid state pins. You can 'cheat' with a meter.

Set your meter to 10-20 VDC range, or DCV if auto-ranging. Connect black lead to TP2 on AUX board.

Probe with the red lead TP1. Should see ~+5VDC.

Now probe J1 pins 1,2,3,4,7,8,9 and 10. This would be a pulse signal on the logic probe. Your meter will 'average' this signal to ~2-3 VDC. What we are looking for is one that is solid +5 VDC or solid 0 VDC.

Whatcha got?

OK, my bad, I was referencing the 8BD aux schem. Here's KISS:

kiss aux lamp inputs.jpg

So pins 1,2,3,7,8,9 and 10 are the ones to probe, which you did. They look good except pin 3 @ .16, which is a constant LO, and pin 10 @ 5.3 which is a constant HI.

Disconnect J1 from AUX driver board. Enter Lamp Test. Now probe pins 3 and 10 in the plastic housing. Are they still 3=.16 and 10=5.3?

OK, it looks like pin 10 recovered when disconnected, so something on the board is holding that line HI.
I still don't like pin 3 being held LO as that is the Clock signal(s) for U1 and if I understand properly the outputs can't toggle (to turn lamps on and off) unless the Clock line transitions from LO to HI.

If I have time tonight, I will do some checks on my 8BD AUX board inputs and see if I can confirm what we should be seeing on those lines.

OK, I have some readings for you.

Game in Lamp Test, all lamps blinking. The voltage reading will be jumping up and down in unison with the lamps.

Meter set to 20 VDC range, NOT auto-ranging.

All readings on J1:

Pin 1 (AD1): 1.3 - 1.8 +VDC
Pin 2 (AD0): 1.3 - 1.8 +VDC
Pin 3 (Lamp Strobe): -.1VDC - +.2VDC (minus point one to plus point two VDC)
Pin 7 (PD1): 1.1 - 1.9 +VDC
Pin 8 (PD0): 1.4 - 2.2 +VDC
Pin 9 (PD2): 1.2 - 1.8 +VDC
Pin 10 (PD3): 1.0 - 1.9 +VDC

These are outputs from the MPU. By disconnecting J1 and probing the connector pins you are isolating the inputs from the board. Let's pull that connector again and probe all the above pins. Pin 3 is critical. Reconnect J1 and re-probe the pins. Before, the only change was Pin 10 being held HI (+~3.5VDC or higher).

So how do your readings compare to mine?

I wouldn't do any board work yet. That Pin 3 never getting above or below .16 has me concerned. I think we should meter the other lamp strobe and see what its behavior is.

All the rest of the lights seem to be working properly?

Also a cheap logic probe will increase your troubleshooting abilities exponentially.

http://www.amazon.com/Elenco-Electronics-LP-560-Logic-Probe/dp/B000Z9HAP4

There have been threads where some were suggested here as well.

OK, probe MPU J1 pins 8 and 11, while in Lamp Test. What do you see?

This is still just the K-I-S-S backbox lamps? All other lamps behaving normally?

All right. Let's assume that .16 is a good signal for a moment, and that all the inputs to your board are correct.

Let's probe U1, pins 1 and 13. These should be pulsing outputs that control the other four chips.

Do any of the K-I-S-S letters operate properly?

I looked up your probe model but couldn't find a clear pic of the switches right off.

Anyway, set it to TTL, not CMOS...don't know about the "pulser" part...turn that off if you can.

Connect Black lead to AUX board TP2.
Connect Red lead to AUX board TP1.
Probe TP1.
You should get a HI response.

Enter Lamp Test.
Now we thought we had good inputs, but let's verify with the probe:
J1 pins 1,2,3,7,8,9,10 all should be pulsing. It may also say LO, HI, or both along with the pulse blinking, that's OK.
All pins pulsing?

If yes:
Probe U1 pins 1 and 13
Both pulsing?

[Edit] also, let's probe U1 pins 3 and 11 and see what the clocks are up to.

OK. I thought I read where it had a probe function, but it sounded strange.

Pin 3 is the Lamp Strobe. It should be LO *and* Pulsing (LO led on solid, Pulse LED blinking).

You can leave the game in Attract Mode to take probes.

Probe MPU board: J1 pins 8 and 11, the two lamp strobes. They should both be LO and Pulsing. If pin 11 is, but pin 8 remains LO, disconnect J1 from AUX board and re-probe pin 8. Does it now Pulse?

Pins 3 and 11 are the clock inputs, which is the lamp strobe fed through a 20K resistor. Pins 1 and 13 are the outputs.

What I don't get is that the Lamp Strobe is correct @ MPU, but by the time it gets to AUX IC1 pins 3 and 11 it's no longer pulsing.

There's a detail of the circuit in post #16.

I might would agree AUX U1 is bad, but the two Clocks remaining LO is confusing.

I verified in my 8BD (same 20K/2.2MEG input resistor circuit) that the clock signal should be pulsing at the chip leg (or the output side of the 20K resistor)...so I'm going to say that U1 is bad, keeping the clocks and outputs LO.

I think we have done due diligence to prove that chip has failed, and am comfortable suggesting replacing it.

Ed has them pretty cheap:
https://greatplainselectronics.com/search.asp?pg=1&stext=MC14013&sprice=&stype=&scat=

I hope I haven't led you astray!

Well, that was the hope of the exercise, that you would learn a little bit about how circuits work and how to troubleshoot them. I'm not as educated/experienced as I should be to try to instruct, but I learn as I go too. The helping is the important part!

Let me know how you fare.

Nice! We probably had people shaking their heads wondering why we didn't just shotgun the board, but we only replaced what we HAD to for the repair. No wasted chips, no unnecessary solder work on the board. A fine success!

Enjoy you game...I always liked Kiss even though it's not universally well-received.

I hope to agree with you! I bought a handheld scope a while back and am looking forward to getting acquainted with it on this World Cup I'm reconditioning. It will be my first use of a scope since tech school back in '84-'85. Hopefully a rewarding learning experience!