Tech: Bally Star trek, self test not working.

WintermuteDK

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Jul 30, 2012, 8:41:40 AM7/30/12

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Hi people

I have replaced 5101, 6810, 6800 both PIA6820 and 555 on my Bally MPU
and finally i get seven flashes on startup - and my Star trek goes in to
attract mode:)

But I cant get self test mode to work - when i push the coin door button
or S33 on the MPU nothing happens, not as much as a flicker:/

I tested the S33 button and it works fine.

I am a little lost with this, so any suggestions or ideas willl be
appreciated:)

Thank you in advance.

Brian Andersen

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WintermuteDK

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Jul 30, 2012, 9:06:27 AM7/30/12

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If I ground the associated pin in the mpu, it also doent enter self test
- freaky:/

Regards

dothedoo

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Jul 30, 2012, 10:36:09 AM7/30/12

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Simply grounding the pin won't trigger a switch closure. You need to short the two pins together to allow the signal generated by the MPU to return to the MPU and be read as a switch closure. From what I see shorting pin J3-1 to J2-7 should trigger a self-test switch closure.

Bill Stahly

kul4...@gmail.com

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Jul 30, 2012, 11:08:11 AM7/30/12

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I am not 100% sure on this, but I think the button on the MPU at S33 only clears audits. I would suspect a bad connector on the MPU this goes to the coin door. So, the wiring to the coin door, the coin door switch, or a bad pin, loose fit, or other connectivity problem would be my first course of action.

Pinball Bob

Pinwizman

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Jul 30, 2012, 11:14:35 AM7/30/12

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I too would suspect a bad connector on the MPU this goes to the coin
door.

Rob H.

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Pinwizman

WintermuteDK

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Jul 30, 2012, 11:50:53 AM7/30/12

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Yeah but recall reading somewhere that later it is daysichained with the
coin door switch - but maybe I am wrong on this.

And still nothing happens when I push the S33 or the coindoor switch -
shorting the to pins also has no result:/

Thanks for the reply

TheKorn

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Jul 30, 2012, 2:11:11 PM7/30/12

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dothedoo <ws3...@att.com> wrote in
news:04e52988-1217-4235...@googlegroups.com:

Bill has the right idea here. Though A4J2-7 is marked as not used in the manual.
My guess is that you'd need to short A4J3-1 to either A4J3-2 or A4J3-3, but that's a
bit of a WAG.

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seymour.shabow

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Jul 30, 2012, 6:28:32 PM7/30/12

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WintermuteDK wrote:
> Yeah but recall reading somewhere that later it is daysichained with the
> coin door switch - but maybe I am wrong on this.
>
> And still nothing happens when I push the S33 or the coindoor switch -
> shorting the to pins also has no result:/
>
> Thanks for the reply
>
> Brian Andersen
>
>

S33 does nothing except clear audits; it does not enter test mode nor
advance within it, etc.

Do the test with the pins like Korn suggests, pin 1 should be the self
test input, and yes, you do just ground it momentarily.

MrBally

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Jul 30, 2012, 7:06:32 PM7/30/12

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Install any Bally system 1 MPU in your game, once it powers up, see if
you can enter test mode via the coin door test button. You will
immediately isolate whether it is the board or cabinet wiring. Borrow
a board from someone or take yours to somebody with a Bally SS pin
aind install yours in their cabinet. If you can get into test mode,
you now know your board is good an the problem is in your game's
wiring.

Bruce

bara...@gmail.com

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Jul 30, 2012, 7:29:18 PM7/30/12

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I am betting on cracked header pins. Bottom right connector as you are looking at the board face up.

If the header pin is cracked jumping it at the connector will not do anything.

WintermuteDK

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Jul 31, 2012, 5:06:47 PM7/31/12

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Thanks for the input people - I will have a look at the pin and get back
with either result:)

Regards

AVP Pinball Division

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Aug 2, 2012, 9:53:20 AM8/2/12

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"WintermuteDK" <Br...@flekz.dk> wrote in message
news:Wintermut...@rrgparchive.com...

This is a very simple circuit. U10 pin 40 ---> 100 ohm resistor ---> J3,
pin 1 ---> Self-Test switch ---> Solenoid Driver Board J2, pin 7 (dedicated
ground). This circuit on the MPU is in the corrosion zone so even after
changing the socket you must ring out all of the traces and may additionally
need to replace connectors at the harness.

Get your multimeter, set it to the 200 ohm/continuity scale. Put one probe
on top of U10, pin 40 right at the IC. Put the other probe at J3, pin 1.
You should read about 110 ohms. If not then check the solder pad to the
pin. If you now get continuity you need to double-check your soldering to
the socket for U10. The other side of the self-test switch grounds out on
the solenoid driver board: J2, pin 7, self-test dedicated ground return.
This is a simple ground, not a strobed line as others have said. All of the
headers here are candidates for potential broken solder joints.

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email: ser...@AVPpinball.com

WintermuteDK

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Aug 2, 2012, 1:49:01 PM8/2/12

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Hi

All seems to be fine, i have 110 ohm from J3 pin1.

I tried grounding pin 40 and still nothing happens:/

Thanks for helping out

CactusJack

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Aug 2, 2012, 2:32:51 PM8/2/12

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If grounding the pin on the PIA (U10) doesn't go into test, try swapping
the PIAs (6821). It sounds like that input is bad.

RB

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CactusJack

WintermuteDK

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Aug 2, 2012, 2:48:19 PM8/2/12

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Hi

I tried both and the problem is the same - i measured 5v on pin40 and it
drops to 0.3v when I push the self test button.

Could it be a higher priority interrupt hanging? Or a bad Eprom?

Again thanks for all your input people:)

Regards
Brian Andersen

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WintermuteDK

WintermuteDK

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Aug 2, 2012, 4:11:21 PM8/2/12

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Hi people

Steve Kulpa solved my problem(Thanks Steve).

It was a bad socket connection on U9 pin38 - now it works like a charm
again:)

Thanks for all your input and help people:)