Lost World
Bally, 1978All new boards except for lamp driver. This is an ultimate SDB. Test voltages from the power supply are all in spec. The 1/4 amp FB high voltage fuse blows as soon as I turn on the power switch. For the moment, pinwiki is no help, as I get a message saying I’m the 5 billionth something and please click for prize when I try to open the Bally/Stern section.
Any thoughts appreciated!!
Sorry that the Wiki is down right now...Casey is working on that.
But, even better, you have one of the authors helping now.
Disconnect all displays.
Replace the fuse.
Power on.
If the fuse blows, the issue is on the PDB. If not, then one (or more) of your displays is shorted. At this point, it's trial and error. Connect the least likely suspect display based on simple visual assessment and power on. Repeat until you find the shorted display.
--
Chris Hibler - CARGPB #31
http://www.ChrisHiblerPinball.com/Contact
http://www.PinWiki.com - The Place to go for Pinball Repair Info
I think F2 should be 3/4 amp slow blow.
Disconnect J3 on the rectifier board - does the fuse blow? If yes - check the diodes.
If no - disconnect pin 8 on the J3 connector on the driver board. If the fuse blows you have a problem in the high voltage section.
If no - you have a short in one of the displays.
Thanks guys - Chris, you’ve confirmed what I suspected. All the displays look pretty suspect... And Bob, this is a replacement SDB, so 1/4 amp is the correct fuse.
Now I just gotta find a pile of 1/4 amp fuses. Only had two in my stash...
Moot point. Further examination of the displays shows 4 of 5 are outgassed. I’m replacing with pinitech LEDs, so the high voltage circuit isn’t going to be used.
Cheers!!
Hello,
I am hijacking this post because I have a very similar (exact) problem that I am afraid has at least 3 of the displays shorted at this point....possibly all 5.
I have a new to me Bally Star Trek that I have never seen working. I now have everything working except the displays. Game plays, all switches and coils work etc... but when I power on with the display there is a short (it appears) around R1 R3 R5 and C2. I have checked everything I can think of and it just doesn't make sense why these are shorted. Resisters all check out, even checked the transistors, the Zener diode and the capacitor...and still nothing. 170VDC and the +5VDC are good and solid.
Can displays just short out? Is it in the glass? These do not appear to be burnt or have other signs of tampering. I have reflowed the connector pins but the three displays I spoke of definitely short when the game is on and burn out the 3/16 fuse on the Solenoid board.
Any ideas?
Thank you.
I think the best solution is the pinitech LED replacements. They look great and are likely to perform long after my kid has inherited these games.
I've repaired a few Bally/Stern displays from this era, but they were relatively simple issues that were corrected by reflowing solder or replacing a single component to fix segments that were out. There is lots more here:
https://pinwiki.com/wiki/index.php?title=Bally/Stern#Displays
https://pinwiki.com/wiki/index.php?title=Bally/Stern#Display_problems
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