From Newsgroup: rec.games.pinball

I tried searching for the answer, but couldn't find anything similar. I will continue searching. in the meantime hopefully you can help...
I have a Bobby Orr Power Play, which has worked without any issues for years. Now sometimes when we turn it on the play field and back glass lights come on but nothing else happens - no score LEDs, no flashing lights - nothing. Pressing the start button does nothing. Other times we turn it on and it works just fine. Any pointers on where to begin troubleshooting?
The last time I had to dig in to a machine was about 7 years ago, so I'm extremely rusty. Any help is GREATLY appreciated!
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From Newsgroup: rec.games.pinball

So the LED on the MPU comes on solid (doesn't flash) and stays on. I changed the batteries just in case, but no luck. The manual for this machine says the A4 board needs to be replaced with these symptoms.

Is there anything else I can try before blowing money on a new board?

pinrepair.com does not include repair guides for 1978 Bally machines (unless I'm reading that wrong). Is there another place to find early Bally repair guides?
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From Newsgroup: rec.games.pinball

Never mind, I found it:
http://techniek.flipperwinkel.nl/ballyss/rep/index1.htm

If I keep digging it looks like I'll find the answer sooner or later. If you have any guidance to speed my quest - it's greatly appreciated!

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From Newsgroup: rec.games.pinball

On Thursday, May 14, 2020 at 5:33:09 PM UTC-5, Clark wrote:

I tried searching for the answer, but couldn't find anything similar. I will continue searching. in the meantime hopefully you can help...

I have a Bobby Orr Power Play, which has worked without any issues for years. Now sometimes when we turn it on the play field and back glass lights come on but nothing else happens - no score LEDs, no flashing lights - nothing. Pressing the start button does nothing. Other times we turn it on and it works just fine. Any pointers on where to begin troubleshooting?

The last time I had to dig in to a machine was about 7 years ago, so I'm extremely rusty. Any help is GREATLY appreciated!

I would reseat all socketed IC's. Reseat the connectors, and check voltages. --- Synchronet 3.17c-Win32 NewsLink 1.112

From Newsgroup: rec.games.pinball

On 5/15/20 6:34 PM, Clark wrote:

So the LED on the MPU comes on solid (doesn't flash) and stays on. I changed the batteries just in case, but no luck. The manual for this machine says the A4 board needs to be replaced with these symptoms.

Is there anything else I can try before blowing money on a new board?

pinrepair.com does not include repair guides for 1978 Bally machines (unless I'm reading that wrong). Is there another place to find early Bally repair guides?

The LED locking on gives a bit of a clue. See the links to the guides
below.

Fixing a non-booting Bally MPU can be a challenge. Pinwiki has a good troubleshooting guide.

https://www.pinwiki.com/wiki/index.php?title=Bally/Stern#MPU_boot_issues

Bally also published a troubleshooting guide. I think this is it:

https://www.manualslib.com/manual/535941/Bally-Electronic-Pinball-Games.html?page=3#manual

Clay used to have a great guide, but it is no longer online.

Frequently, the cause of early Bally SS MPU failures is battery leakage
on the lower left. If you have any of that, it is necessary to
neutralize it, fix the traces and sockets, then replace many of the components. As MySeeburg mentioned, sometimes you can luck out by
re-seating the ICs.

--
http://orcalcoast.com/
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From Newsgroup: rec.games.pinball

On Sunday, May 17, 2020 at 9:04:35 AM UTC-7, LexingtonVAPin wrote:

On 5/15/20 6:34 PM, Clark wrote:

So the LED on the MPU comes on solid (doesn't flash) and stays on. I changed the batteries just in case, but no luck. The manual for this machine says the A4 board needs to be replaced with these symptoms.

Is there anything else I can try before blowing money on a new board?

pinrepair.com does not include repair guides for 1978 Bally machines (unless I'm reading that wrong). Is there another place to find early Bally repair guides?

The LED locking on gives a bit of a clue. See the links to the guides below.

Fixing a non-booting Bally MPU can be a challenge. Pinwiki has a good troubleshooting guide.

https://www.pinwiki.com/wiki/index.php?title=Bally/Stern#MPU_boot_issues

Bally also published a troubleshooting guide. I think this is it:

https://www.manualslib.com/manual/535941/Bally-Electronic-Pinball-Games.html?page=3#manual

Clay used to have a great guide, but it is no longer online.

Frequently, the cause of early Bally SS MPU failures is battery leakage
on the lower left. If you have any of that, it is necessary to
neutralize it, fix the traces and sockets, then replace many of the components. As MySeeburg mentioned, sometimes you can luck out by re-seating the ICs.

--
http://orcalcoast.com/

The last time I did extensive repairs on this machine (many years ago) i moved the batteries to an external dock and it's doing fine.

Thank you both for the suggestions! I hope to find time soon to do more troubleshooting. I'll post the results when i can.
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From Newsgroup: rec.games.pinball

...four months later...
It''s too smokey outside to do any yard work or even woodworking in the garage, so it's down to the basement to finally look at this machine again.
- when I last worked on this machine, about 7 years ago, I replaced the onboard battery with an external dock. There wasn't any leakage from the onboard, and this machine worked fine for the last 7 years. At that time the issue was a bad rectifier board, which I replaced.
- today I re-seated the ICs and checked voltages. my voltage readings are low at all MPU test points:
TP1 - 3.7
TP2 - 9.2
TP3 - 20.7
TP5 - 3.7
I'm not sure what low voltages at all test points means. Let me know if you have any pointers. I'm digging back in to the repair guides now in hopes of finding a fix.
Thanks!
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