Are you using the original MPU/Driver interconnect or an IDE cable? Not sure if these boards support the IDE replacement anymore. Sounds like it could be a bad connection between the MPU and driver.

Curious. What does "bullet proofing" the sound board amount to?
I'd remove the fluorescent tube while debugging. The EMI from those things can cause issues at boot, at the very least.
The signals to the sound board come from the driver board. It is important that all of the edge connectors are clean, without oxidation or corrosion.

--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact ... for board repairs
http://www.PinWiki.com - The Place to go for Pinball Repair Info

One edge of the driver board has only two connectors. Both of them should be repinned.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact ... for board repairs
http://www.PinWiki.com - The Place to go for Pinball Repair Info

great plains electronics should have everything except pins for the double sided connectors (which aren't available iirc)

Contacts:
https://www.greatplainselectronics.com/products.asp?cat=77

Extraction tool:
https://www.greatplainselectronics.com/products.asp?cat=140
11-03-0016 (Molex)

W-HT-1884 (Waldom) looks just like the Molex but does not fit properly into these edge connectors.
As you can tell by the price, Molex is real proud of this tool. Some people (me) are too cheap to pay for the Molex tool and make our own. I have a slightly modified jeweler's screwdriver that costs much less and works just as well.

For using the extraction tool with the Molex edge connectors - see figure 2 here:
https://www.greatplainselectronics.com/Datasheets/connectors/Molex/HTA2174.pdf

If you have the IDC type plugs on your machine now - good luck.
Seriously, you can still use the connector shells but they're tougher to get the old contacts out.
Being a Gottlieb 80B - you probably have the IDC type plugs.

They're not really designed to be removed, but it's not too bad. Need to push the locking tab on the pin in hard enough for it to stay down, then try to pull the wire out (which may take some finesse since there's tabs to hold it). Often the pin will come out with the wire, sometimes you need to use a pick or needle nose to pull it out after.

08-52-0072 works well for vast majority of fixes. 08-52-0134 is used when you have real small wires into the connector (can't think of any that small on a Gottlieb).

Those aren't easy to find these days. I'd reuse as many as you can.
Hard to tell from the pic, but that one seems usable still.

That one is still in stock, fortunately.
https://www.greatplainselectronics.com/proddetail.asp?prod=09-01-6041

Check around on Ed's site for others you might need.
Ed is the only supplier that I am aware of.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact ... for board repairs
http://www.PinWiki.com - The Place to go for Pinball Repair Info

Yes. But it isn’t really needed for the type of connector pictured. I use a small screwdriver to smash the pin from the back, through the small rectangular hole where the pin tang snaps in to hold the pin. The pin can be easily pulled out after this.

To repin the black connector used to connect MPU and driver board, you do need that tool or something like it.

—
Chris Hibler - CARGPB #31
Http://chrishiblerpinball.com/contact
http://www.PinWiki.com/ - The new place for pinball repair info

It doesn't need to be very small, most standard ones will work. It doesn't go in from the side, there's a little window on the front of the connector for each pin, where you can see the metal pin has a small tab holding it in against the edge of the window.

Have you checked to see that the sound board is being reset by the MPU?
—
Chris Hibler - CARGPB #31
Http://chrishiblerpinball.com/contact
http://www.PinWiki.com/ - The new place for pinball repair info

all the sound control lines sound 1,2,4,8,16 and 32 if used must be a 5v high for the reset to work. I would check all the lines for 5v if one is low the card the reset line will not reset the card

exactly black on ground red on lead on the line.....I don't have your particular machine but all system 80B s use the same architecture the MA766 and the 886 use the same type commands. they use pull up resistors on the sound card and negative triggers to control the music and sounds ...most machines use lines labeled sound 1,sound 2,sound 4 ,sound 8 and sound 16 to create 31 possible triggers. During the game there is also a sequence that resets the board ......look on your schematics for these lines and they should all read 5 volts the triggers are so fast that you can only see them with an O-scope and you wont pick them up with a meter other then sound 16 which is controlled by the driver board under certain conditions so during the game it will be high or low but at the start it should be high. The same goes for sound 32 but it is not used in most games

if you haven't done the ground mods use the 5v ground on the sound card

yes sound 1 thru 8 comes from the mpu and usually sound 16 from the driver board

right if one of the lines is shorted to ground the board will not reset at the beginning of the game only when you reset the card manually like you spoke of earlier....you can turn on the game and hit the start button and then do you checks before you shoot the ball

exactly

You are thinking of this wrong.
Those signals are tied to a pull-up resistor on the sound board.
Unless the MPU pulls that signal to ground, all of those pins should be at 5VDC (or close).
If you remove that connector and measure power at each of those pins, they should read 5V.

The game makes sounds by the MPU pulling 1 or more of those pins low, indicating a particular sound to play or an action to take.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact ... for board repairs
http://www.PinWiki.com - The Place to go for Pinball Repair Info

I can't see what connector that is in the second pic.
The first one looks normal to me.
While some pins are connected on the sound board PCB, they won't necessarily have a corresponding offboard wire.

With P1 removed, power on.
Each pin on P1, should measure 5VDC due to the onboard pullup resistor.
Black on backbox ground.
Red on each pin one at a time.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact ... for board repairs
http://www.PinWiki.com - The Place to go for Pinball Repair Info

GTB (resized).jpg