Gottlieb Close Encounters of the Third Kind (Gottlieb, 1978) Gottlieb System 1 Boot Problem

[jeffro1]

Hello All, I'm working on my 1st machine , Close Encounters, and I'm having a boot problem. I have done all grounding mods, repinned all connectors, defeated the slam switch, change caps in power supply, but I'm having a problem with machine booting properly. At times when powered up it will boot with 5 sec delay on 1st try and play perfectly but other times you must power on and off several times to make it boot. When it does not boot right it does several different things. At power up it might lock on sound and coils and playfield scoring lights or other times just a few playfield scoring lights will light up but no boot. Sometimes the scoreboard will turn on right away with all zeros (but I know its not slam switch because it has been defeated and zeros dont roll or flash). When I check power supply it always has the proper voltages ,+5v and -12v at power supply and caps on cpu board. Since it does boot properly at times there must be some kind of short somewhere, I'm just stumped at figuring out where and it's driving me nuts. The reset circuit on CPU has also been updated (I forgot to mention that). I know there are new boards I can replace it with but money is kinda tight now and cant afford it for at least a few more months. I was just hoping someone here maybe had the same problem before or someone knows what I should check next. I look forward to seeing an answer and thanks to anyone who can help! Jeffro

 

[spalmer]

Sounds more like a bad connection than a short. I would replace all of the card edge connector pins. They cause a lot of issues on these older machines. You can find them here.

http://www.mouser.com/Search/ProductDetail.aspx?qs=ZZBj1wiNDbnEqpNpmJNYsg==

You will need a crimping tool.

http://www.mouser.com/ProductDetail/Molex/63811-1000/?qs=u6Gr9/Nt%2b/9oql%2bd80isUQ==

And a Pin Extractor to get the pins out of the plastic housing. Make sure to do 1 at a time so you don't get the wires back in the wrong place.

http://www.mouser.com/Search/ProductDetail.aspx?qs=GNoxSpue3Y37z3Uq0MzqvQ==

 

[jeffro1]

As I wrote in my post, I have changed every pin in the connectors already, done all grounding mods, change caps in power supply, slam switch mod,
and when I try to boot with all connectors disconnected, except power supply and display connected, it still only boots intermittently. I'm just stumped.

 

[spalmer]

Sorry, I did not see the repinning of the connectors.