(Topic ID: 314036)

Power Play Pinball - Bally 1978 - will not boot - help!

By carniello

1 year ago


Topic Heartbeat

Topic Stats

  • 14 posts
  • 4 Pinsiders participating
  • Latest reply 1 year ago by carniello
  • Topic is favorited by 1 Pinsider

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#1 1 year ago

Hi All!
I'm working on a friends Power Play pinball. So this is the story: Games was working fine, then they had problems with that center pop up between the flippers. I believe it was not going up (I inspected and no visible burn or damage). So, I powered the game on and watched the led, only got one flash . Tried again and got 7 flashes but no displays. Tried again and one flash. Tried again and 7 flashes then it would keep repeating again with 7 flashes. Very intermittent.

I checked all voltages, and they were good.

Ok, so I pulled off all plugs on main board except plug with voltages. Same thing. Very intermittent. 1 flash, 7 flashes, 7 flashes repeating .

Sockets on main looked ok. Battery is off board, no corrosion. So I'm thinking main board.

Get the main board home, hooked up my computer power supply with 5, 12 volts to test main board. It will boot fine every time.
I waited a day and tried it again several times. The leds always flash 7. WOrks perfect on test power supply.

Now I'm wondering what the issue is? Regulator board?

Any suggestions?

John

#2 1 year ago

The power leaves the rectifier board but then needs to go thru molex connectors to the -22 solenoid driver board where it will get filtered and then sent back out to thru more molex connectors finally arriving at the MPU. Repin all the 0.100 molex plugs on the MPU and -22 SDB as a start. Then reflow all header pin solder joints on the rectifier board, sdb, and MPU.

Because this is intermittent, and you tested it on a power supply with success, there is no longer a need to diagnose further. Your problem is flakey connection which are super common on this platform of game.

#3 1 year ago

Also forgot to mention the 0.156" molex connectors (usually) do not need repinned unless they are burned. But they always need the pins reflowed. (Williams always do).

You will also want to goto pinrepair.com and perform all the modds to the -22 SDB. You will essentially be making some jumpers on the back of the board to improve grounds, and another mod to jumper the power to it does not need to enter and exit thru a molex pin that is prone to overheating. These mods are very important for stability.

#4 1 year ago

Can you post a video of the MPU booting? Specifically we need to see the flashes and if the battery is still installed and if there is any past battery damage.

Are you counting the initial flicker as a flash? The LED should flicker, indicating it has power and the board is going to boot, and then flash once, pause, and flash 6 more times.

1 flash means there is a problem with the program chips. 6 flashes means the 43v is not present. An old battery is a ticking time bomb that blows up the entire reset circuit.

#5 1 year ago

Hi All,

I do get the initial flicker flash, flash once then the proper 5 flashes (I do not get the 6th flash because of missing +43 volts on computer power supply).

I did check the two test points on regulator board for 5 volts and they were spot on. I did check 5 volts going to main board connector before I plugged it in and it was 5 volts (it did drop to 4.95 after I plugged it in).

* I will re-pin those power supply connectors.
* I will reflow solder connections.
* I will add jumpers on back of regulator for 5 volts mod.

I will update next week when I go back out to my buddies.

Thanks ,

John
www.pinballmemories.com

#6 1 year ago

Ok, I decide to add jumper on my bench test to get that 7th flash. Video is here:

I think I have a main board broblem...

#7 1 year ago

The single flash indicates it's failing at the U7 6810 RAM test.
We have seen in the past U7 issues cause non stop LED flashes.
So focus on U7, maybe it's faulty, maybe the U7 socket has a temperamental connection.

#8 1 year ago

if u7 is an AMI brand just change it. from the photo that board looks to have the good sockets but in in doubt sometime you have to remove and clean hidden acid from under them,.

#9 1 year ago

Hi All,

I received the U7 chip 6810 ram and replaced it. I popped it in and tested the main board with my pc power supply.
It has successfully booted every time so far! I booted it about 10 times. I will continue to boot this weekend as I will be
installing the board back into the machine next week.

I did replace a ton of chip sockets. They were not loose as I was not able to pull chip out of socket. I'm hoping I did not create a problem

I will update this post with results.

Thanks all for your responses!

1 week later
#10 1 year ago

Ok, the game booted properly. Everything working correctly except for button on inside coin door. It looks like it might of been wired wrong so i used a jumper from mpu to solenoid board (i cant remember points but I found them on schematic) and I was able to get into diags and set replay for hi score of 10,000 (because Bally cannot be set on free play).

Then something weird happened after I exited diags.

Player number two mirrored the credit /ball count display. Also, the lights for number of players were all lit (1-4).
Machine still worked but it is light the light matrix and displays are wrong.

What do you think happened?

John

#11 1 year ago
Quoted from carniello:

Player number two mirrored the credit /ball count display.

Check the red-green wire running on the coin door to the slam and coin switches. Somewhere it might be shorted to the metal door/assembly (i.e. ground).

#12 1 year ago

I had my friend unplug the coin door and problem went away..
I have go back and check those wires on the door...thanks QUENCH!
I will update when resolved.

#13 1 year ago
Quoted from carniello:

Player number two mirrored the credit /ball count display. Also, the lights for number of players were all lit (1-4).
Machine still worked but it is light the light matrix and displays are wrong.

This exact same thing happened to me a couple days ago. A wire from the left coin chute switch came loose and was shorting against the frame. Unplug the front door and if the problem goes away that's what your looking for.

#14 1 year ago

Hi all, second problem is resolved. Had a wire on coin door touching ground. Everything is working correctly.
Thanks everyone for your input! GOD BLESS YOU ALL!

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