1987 Spring Break MPU Not booting

Stinger357

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Just got a new spring break pinball from 1987. The GI lights comeone ok but the cpu wont boto it is led flashing slowely. What can I do to see what the problem may be. I need detailed instructions on how to troubleshoot this. I disconnected the power supply 4 pin to the cpu and it still would not come on. Also no battery damage whatsoever on the machine. If anyone can help me trouble shoot this would great appreciate it!!

Thanks,
Aubrey
 
Man, you got your hands full on picking up a Gottlieb on the fritz...

I'm not sure what you are testing, power supply? On system 80b games to test the power supply you need to take the black lead to a ground. I usually connect it a the screw holding the ground braid in the backbox. The red lead I believe is any of the 4 header pins on top of the power supply. It should be around 5ohms. There is a pot to adjust this BUT sometimes this pots is bad....

As OZ said check Clay's site for futher info....These Gottliebs had grounding issues which could also not make the mpu not boot correctly and a myriad of other problems......
 
It gets power and GI light come on like I said before, But the display wont show up and the game will not initialize. What's my next step in troublehsooting this issue, I have used repair guid which provided no help for begineers like me...Any step by step procedure to determine what is going will help. Adjusting the power pot does nothing to it. Cant go into setup no display at all...All fuses seem ok. I am thinking it is a power supply +5 v issue since this machine was brought over from france. Anyhelp would be appreciated.

Now the LED is not flashing just stating on solid.
 
Ok from the power in the power supply driver and ground I am getting 6.3 voltd...Which shoud be plenty for the game to boot up. Also I had it on 5.3 same thing. How do I tell if the CPU is bad, the repair guides states to unplug all connectors the CPU driver board then plug in U2 to see if the CPU comes up...should that be done? Also any other troubleshooting would be helpful...thanks,.

the Led is not coming on anywhere also. Maybe a quick flash when it is powered on.
 
Any help on this? I really would like to know what is wrong with this spring break. I am getting a constant 5.3 volts from the cpU J1 connector ok. What else can I try to isolate the problem. The LED is on solid now...if that makes any difference.
 
Well Tinkering around with it I got the led to go off completely. and also the display is showing garbage so I am thinking my voltage is not correct. What do you all think?
 
Well the latest is I still can't get the machine up and running. I can tinker with it and get a garbaled display, but not attract mode nor game start. I am beginiing to think it is the power supply driver. Or the MPU itself is bad...I am having my tech come over next week to look at it. But I would hope I could repair it myself. Adjusting the pot on the voltage seems to effect it quite a bit but will not bring it up. Any more ideas on what I can try. I am getting .5v dv to the pot to ground so it is getting proper voltage.
 
Don't turn up the pot too much, you can fry some componets on the mpu....Like I said previously It could be ground issues...Are you good with a soldering iron? If you're new you might have you're tech look at it. Is there a liitle board piggybacked on the mpu board?
 
Where should I be polling from to determine if the cpu is gettting enough power +5vdc. Can someone let me know where I need to put the red cable and the black cable to determine what I am getting to the cpu.

Thanks,
Aubrey


Also why is it my sound board is the only board with an led? I thought the CPU and another board had an led on it also. I got this from an import from france and it was converted to 120V DC.

Please advise.
 
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There is a cap, I believe it's c2, on the mpu board...It should be by the power supply connector...Take red lead on +, black on - and it should be around 5v....That means you have the correct voltage anything less and you could have a bad component on the mpu or driver board if that's connected...

The single led is normal on the sound board...Blinking=good, non=not good...
 
Unfortunately repair information specific to System 80B is kind of scarce online. Sure there is a ton of information on System 80 but 80B is really a different animal.

As far as checking the +5VDC at the MPU goes I would suggest checking right at an IC on the board. Black on ground and red on VCC. Pick an IC and look up the data sheet. It will tell you the pinout and from there you can determine where to put your leads to check the voltage. That's one way...

Alternatively there should be an electrolytic cap across the +5DC somewhere on the board. You could check there too.

If you have a tech coming over you should get him to show you some of this stuff. If you're coming from a "where do I put the leads" perspective there is really no easy answer for you. It's going to take some time and some learning to figure this stuff out.

EDIT: or just do this :)

There is a cap, I believe it's c2, on the mpu board...It should be by the power supply connector...Take red lead on +, black on - and it should be around 5v....That means you have the correct voltage anything less and you could have a bad component on the mpu or driver board if that's connected...

The single led is normal on the sound board...Blinking=good, non=not good...
 
Where would I locate C2 on the MPU? It is labeled really small..where would it be located near the power 4 pin connector or where? I am too new at this and the tech wont be out till monday. So I am trying to determine if the MPU is getting proper voltage....Can someone post a pic with the exact location of cap C2 so I can check with my DMM thanks.

I have attached pictures of the backbox and see if you can help me any better.
 

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Can Someone show my a pic of where the C1 capacitor is so I can put my DMM on it and black to ground to see if the cpu is getting .5vdc...I cant seem to find the c1 capacitor...the labels are real small and cant read them...also the led on the sound board is now out....Dont know why..also what is the small circuit board to the right of the cpu I have 2 wires loose on it could that maybe my problem.

But the GI lights come on and the backlight comes on but the led is not flashing or even on..it was flashing when I first plugged it in..now it wont...So did I screw something up?>
 
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OK I tested C1 and no voltage coming to it..but the power supply 4 pin has 5.3 voltage to it.
 
Are we talking possibly a bad chip or Eprom for the cpu or something else? How can I issolate what the bad chip is. I did get the display on for 10 min and it showed 6 6 6
 
Where is U1 located I cant seem to find it....should I test to see if it is getting +5vdc?

I feel like I am talking to myself here..any system 80 guru's around?
 
I am now getting 2.30vdc from my DMM on the pot...I dont know why I adjusted up and down and it still says 2.30 any ideas?
 
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