My Twilight Zone is in the Twilight Zone and started acting up. When I turn it on the clock runs backwards continuously...it will not stop. Can someone point me in the right direction to correct the problem?
Thanks
My Twilight Zone is in the Twilight Zone and started acting up. When I turn it on the clock runs backwards continuously...it will not stop. Can someone point me in the right direction to correct the problem?
Thanks
Check the bend in the wires going to the clock boards plug. Grey wires. If you have opto switch problems. These go bad over time. With heat and vibration + how serious of a bend it it is going into the clock.
They either break internally or just pop out of the molex enough to be intermittent.
I've fixed 2 different TZs clock issues because of that stupid factory bend.
But it could be the optos themselves. Dirty, cold solder or just bad.
Also, this is a known issue with the old clock boards with the hot incandescent lights on them. The heat tends to mess up the board. New boards have cool leds
Also check ribbon cables in back. I've seen this issue with a loose cable particularly the very long cable.
Quoted from gsrogers:My Twilight Zone is in the Twilight Zone and started acting up. When I turn it on the clock runs backwards continuously...it will not stop. Can someone point me in the right direction to correct the problem?
Thanks
If it starts going backwards AS SOON AS POWER IS TURNED ON and before the "TESTING...." screen is cleared, then you either have a bad transistor driver on the power driver board OR the transistor driver on the motor driver board is bad.
If it doesn't start going backwards until AFTER the "TESTING..." screen, then look at what others above mention - bad optos, bad cables, etc.
The clock has been rebuilt with new board and in test mode the optics are registering. I have reseated and messed with the ribbon cable with no change. Argh
Quoted from Coyote:If it starts going backwards AS SOON AS POWER IS TURNED ON and before the "TESTING...." screen is cleared, then you either have a bad transistor driver on the power driver board OR the transistor driver on the motor driver board is bad.
If it doesn't start going backwards until AFTER the "TESTING..." screen, then look at what others above mention - bad optos, bad cables, etc.
Coyote, you are spot on....the clock goes backwards as soon as you turn on the pin. It stops for a few seconds during the boot up sequence and restarts backwards constantly after boot up. Clock board is not original and was fully rebuilt a few years ago. I will take a look at the schematics to track down the transistors. Thanks to all....please continue with additional tips.
I have a similar issue, my clock will start to spin continuously after the machine has been on for about an hour.
Guessing it is the incandescent heat/ board issue.
I was going to buy a clock board from the german guy, but he didn't respond.
Anybody have any recommendations about which of the other boards is the best?
Quoted from Purdue:my clock will start to spin continuously after the machine has been on for about an hour.
Guessing it is the incandescent heat/ board issue.
Not likely. If optos are bad, the game will eventually give up, give you a credit dot, and flag the clock as bad. Likely, the large motor-transistor on the motor driver board is overheating, and going bad.
I had this happen to mine a few years back and it was the motor board under the playfield that needed to be replaced.
Quoted from Coyote:Not likely. If optos are bad, the game will eventually give up, give you a credit dot, and flag the clock as bad. Likely, the large motor-transistor on the motor driver board is overheating, and going bad.
Thank you for the response. Much appreciated.
Ok update. The problem is on the D.C. Motor Control Assembly PCB (A-16120). I tested the game with a known working replacement one and game works great. I found an article that talked about my same problem and replacing the 4N25 optoisolator (U1) on the A-16120 board fixed the issue. I will update after replacing this chip.
Thanks, Garry
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