Twilight Zone
Bally, 1993My roommate was playing TZ and he said the free credit loud knocker went off three times then the whole machine powered down (except for a few aftermarker LED's - see below).
When I power it on - all that comes on is are a few of the aftermarket LED light mod's I have installed. I have pulled these off so they aren't the trouble. I have also tested all the fuses and didn't find a bad one.
Also the #2 and #4 LED's on the Power Driver Board are not illuminated.
Anyone have any ideas?
#2 is high power sense and should normally be ON while right next to it, #3 should be normally OFF. #4 is your +5 volts and without that you're dead in the water.
Check fuses first. Don't just look at them, take them out and check with your ohm meter.
In particular look at F101, 102, 103, 104, 105 and F111, F112 for the high voltage and F113 for the +5vdc
Cliffy,
Thanks for the reply.
Tried all those, they are all good. Did notice when I pulled off F112 that it was a 10A 32V non SB, when the book calls for 7A, SB. Could that have done some damage. Only had this TZ two weeks.
Yeah. Overfused like that means it probably had a leaky bridge rectifier and was blowing the fuses. Someone obviously just upped the fuse size instead of finding and fixing the cause.
F112 is the fuse for BR3 ac voltage input. When you remove that fuse you cut out all the high voltage.
And yes, pulling F113 removes the ac input voltage to BR2, the 5 volt power supply bridge.
I suspect you have a shorted diode in BR2 and this is fairly common. It's usually the first bridge rec to go. Hopefully you're handy with a soldering pencil 
Well now I did it. Pulled the entire power driver board to swap with wh20 to check and see if I should just send the board out for repair (I'm not handy with a soldering pencil )
The Wh20 board worked in TZ initially when I powered it on but the DMD was now dead. Turned it off waited awhile then turned it back on and nothing. Swapped it back to Wh2o and now that one is dead as well (ie the original problem TZ had now wh20 has with the original wh20 board as well)
Now I'm gonna cry cause both my machines are bustimicated.....and I wanted to play some pinball...
Anyone have any idea what is causing this?
Quoted from Waldo:Well now I did it. Pulled the entire power driver board to swap with wh20 to check and see if I should just send the board out for repair (I'm not handy with a soldering pencil [
The Wh20 board worked in TZ initially when I powered it on but the DMD was now dead. Turned it off waited awhile then turned it back on and nothing. Swapped it back to Wh2o and now that one is dead as well (ie the original problem TZ had now wh20 has with the original wh20 board as well)
Now I'm gonna cry cause both my machines are bustimicated.....and I wanted to play some pinball...
Anyone have any idea what is causing this?
Go back and check your connections on that board
I guess its too late to say I never recommend that kind of shotgun approach 
When we do a board swap for testing we don't plug in anything except power to begin with. Then the switch matrix and if all is well the solenoids and flashers one section at a time.
All is not lost. You should be able to diagnose the wh20 board easily by led's and fuse checks. I'm betting a fuse blew on the HV supply which powers the dmd.
I must have been tired last night. Accidentely put the bad board into WH2O - duh. So the original issue is still the only one I got. Gonna call an expert over since there is still issues even when a good power driver board is in the machine....
Thanks for the replies and I'll keep checking in case someone has more ideas...
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Cape Canaveral, FL