I'm sure you've done it but double and triple check every connector you broke to pull the board, one by one, that it's in the right mate and that it's a good connection. Then look around for things you didn't touch on purpose to see all is as it should be (no broken soldered wire connections, etc). Disconnect the MPU power cable and take readings on the power supply board too, especially making sure you still are putting out a good 5v to the MPU. Also, did you unplug the line cord from the wall prior to pulling the bottom board?

The reason I ask about the line cord is that line voltage is present on the bottom board even when the game is switched off. There's a risk of shorting to ground on any one of the exposed connections (like the transformers) as things/parts are being moving around. But you probably would've noticed that as the spark/flash/noise/smell would've grabbed your attention when it happened!

Still look for a bad connection or broken wire as well as those to the coin door. And check the power supply voltages to verify the MPU is getting the proper 5V it needs to bootup.

When I'm trying to locate a problem, I disconnect all the boards and displays from the game. With only the transformer board connected, I turn the game on and test all power at the fuses. If there's a problem, I find and fix it, then try again. If okay, I turn it off and add the A2 power supply to the game. I turn it on and test the test points on the power supply. If there's a problem, I find and fix it, then try again. If okay, I turn it off and add in the A1 CPU board and the credit display. I turn it on and look for the display to come up. If there's a problem, I find and fix it, then try again. If okay, I turn it off, add another display and try again (Repeat for each display). Then, I add in the A3 driver board and turn it on and look for attract reset and then attract mode of the controlled lights. If there's a problem, I find and fix it, then try again. Repeat for the sound board. By the time you get to this point, your game should be working. Most of the time, it's a connector issue if it stopped working when it worked before. Sometimes, it's operator error, like plugging the wrong connectors together.

Steve

Excellent post with great explains what is important - impatience and haste "switched_OFF"

I usually don't use the insulator at the power supply heat sink, it's an insulator, you want the heat to transfer from the case to the heat sink. Use a little of the compound instead.

Steve

Wire wrap the pin on the IC and solder it to the existing trace.

I wouldn't worry about that trace as long as it isn't touching anything, Since all the traces are on the underside of that board, you can see that pin isn't used.

Steve

So, your mojo is still somewhat intact.

Steve

Oh, that.
Missed it when looking at the photo.
What Steve said.

Do you have a copy of Clay's guide to bulletproofing Gottlieb System 80 machines? If not, I have copies of the CPU repair guide and volumes 1 and 2 of the System 80 repair guides.
If you don't have 'em, you NEED them.
Send me a PM with your regular email address and I'll have them to you tonight.

Greg

Looking at the photo you posted, if it was me, I would reflow the solder on all the pins of that IC. That is the LM723 voltage regulator, is it not?

Greg

Hopefully you have that IC facing the correct direction when you put it back in.

Steve

Yup, correct.

Steve

If you need boards looked at, try contacting Chris H here. He does very good board work and could look at them for you.

Steve

The display voltages (60 & 42) are correct with no load on them. The other readings are not good, we need to determine if the problem is a short on the A2 board. When you didn't have the A2 power supply board connected, what were the input voltage readings for the 8VDC and 12VDC lines? Were or are they normal? Did you replace Q3 on the power supply board? If so, did you check it to make sure it was good first? Is there anything else that was touched on the A2 board?

Steve

As I said before, the 12VDC and 8VDC voltages are not good for the regulated 5VDC. There's another problem going on. With the power supply A2 not plugged in, are all your voltages present and correct coming from the fuses?

Steve

When we talked on the phone, I wasn't thinking straight, sorry about that. I'm going to assume since there is voltage of some kind at the fuses, that they are the correct voltages, I just had you placing the black lead on the wrong place. However, just to be sure ...

Looking at the schematic (now, and not depending on faulty memory), I see that you need to read the F5 fuse power at the bridge rectifier with your red lead on the red-orange-orange wire and your black lead on the red-yellow-yellow wires. Your meter needs to be set on AC. You should see 12VAC or higher with no load.

Next, we need to know what the DC voltage is coming out of the bridge rectifier. Set your meter to DC and put your black lead on the ground buss. The red lead needs to be on the red-black-black wire. You should see 12VDC or higher with no load.

If you have the correct voltages here and you still have no LED's on the A2 power supply, as I said on the phone, it's very possible that the solder around the input connector pins to the A2 has failed and will need to be repaired.

If you don't have a working fuse in F1, you won't get any displays once the power issue is corrected.

Steve

4.1VDC is a little too low to run the CPU board although I have seen it boot that low before. Now the LED's are lit? What's changed? I still think you'll have to re-flow the solder at the header pins before I can say where to look next, they are suspect. Always connectors first, diagnosis second. Remember what I said on the phone, resistance ..... bad.

Steve

Take care abut it !!

Did you measure voltage (+5V) with or without plugged (output) connectors on power supply board ?!