(Topic ID: 145066)

Twilight Zone GND SHORT ROW 1 CLOSED??


By theke

3 years ago



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  • 9 posts
  • 5 Pinsiders participating
  • Latest reply 3 years ago by exflexer
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#1 3 years ago

Hello boys & girls,

My TZ has come up with the "GND SHORT ROW 1 IS STUCK CLOSED" error on start up and will not allow any further action. The game is down for now. Any advice in the next step I can take to trouble shoot this??

I have reset all connectors and ribbons...that is all I have done because I don't know what this is?

Thank you in advance, and I look forward to hearing from you all...

CLW

#2 3 years ago

I guess it means what it says - switch matrix row 1 is stuck. Does it still happen if you unplug the switch matrix connectors? I think that'd be a valid test (others will correct me if not). If the problem goes away, there's a problem in the switch matrix, if it doesn't, the MPU has issues.

#3 3 years ago

Well, I reset all of the connectors and ribbons again...PFM, it is now working. I might check all the individual pins for corrosion/connectivity issues?? any thing else you can think to send me to look at??

falco, thank you for that, those were some of the things I also tried...

Works now...

Hmmmm...

image.jpg

#4 3 years ago

Look at my thread for the exact same issue with JM. It was an easy fix by simply replacing one chip on the MPU.

#5 3 years ago

Check your fuses if you haven't already.

Second thing after that to look at is the chip at U20 on the CPU board. I believe it's a 2803

#6 3 years ago

Thanks guys...

Fuses checked, I will look at and check out U20-2803

#7 3 years ago

Game seems to be fine now but I will keep an eye out for the fore mentioned troubleshooting ideas.

Again, thank you.

#8 3 years ago

That's a strange one. Maybe just a bad contact somewhere. If it recurs, I'd be checking the MPU for dry joints and bad repairs in the switch matrix section. When problems go away on their own, I usually figure it's just a matter of time until they come back, but you never know...

#9 3 years ago

A common issue that causes this is that the slam tilt switch is bend so far up that it is touching and shorting things out. Check it!

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