Syracuse, NY
Does anyone know what it means when on the cpu board the top light is off the middle is flashing and the bottom is staying on on a Twilight Zone. My machine is fried and I'm having trouble diagnosing it. Any information will help.
(Topic ID: 37815)
Linked Games
Twilight Zone
Bally, 1993
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What exactly is fried ?
Not knowing, the first thing I'd check is the voltage test points on the power driver board. See if any are low or missing.
They look like little metal posts sticking up and have a number like TP1 ( test point one ) and things like 50V ( 50 volts ) too.
See if any are low or missing.
LTG : )
Quoted from dwizz:would I do this with the machine on? So does that mean the lights on the cpu board do not telling you anything?
You would need the machine on, to measure power.
I'm sorry but I don't remember the LED codes off hand. I never pay attention to them.
LTG : )
ok thank you, so would I turn it off disconnect it and then turn it on to see? The game does turn on lights up and I can hear it boot up and tell me there is a problem. You responded to my topis about the fried tz two days ago and I am in the middle of checking all the fuses now.
well it is showing two lines on the dmd I posted a pics in a post two days ago here is the link
http://pinside.com/pinball/forum/topic/is-my-twilight-zone-fried
Quoted from Prmailers:Did you make sure the diode in this pic was installed the right way?
It is right. Black end to white wire, silver banded end to far lug.
LTG : )
Quoted from dwizz:Sorry but I'm a little confused about disconnecting the boards. the cpu is working or at least power is going to it what should I look for when I disconnect these?
Leave the CPU and power driver board hooked up.
The DMD driver board and or Fliptronics board, disconnect the connectors to them.
LTG : )
So I found this and I checked the fuse and it was blown I'm gonna go to radio shack tomorrow and hopefully this is it.
"I turn my Game On, and a Coil Keeps Firing On and Off - Why?
Also My DMD is Not Working Too."
This is a fuse related problem too. Chances are good the fuse for the 12 volts (F116 or F109 on WPC95 most often) that feeds the switch optos has blown. Since there is no light source for the optos, this makes the CPU think the opto switches are closed (like there is a ball stuck in an upkicker). The machine is trying to eject the phantom ball as part of the power-on process. Also maybe the Dot Matrix Display (DMD) is out too with nothing on the display or just a single line or garbage. Some DMD displays need 12 volts to function, some do not (brand dependant). Check all the backbox fuses (on WPC-S and prior, usually this is fuse F116 (or F109 on WPC95), which is the unregulated 12 volt fuse (on WPC-S and earlier via BR5).
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