Hello,

I am linking this post

https://pinside.com/pinball/forum/topic/high-voltage-fuse-blows-on-boot-up

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.

Sorry, more information. I rebuilt the solenoid driver board and all the voltages check.

I was able to install an old display and it worked fine but still not sure about the ones that came with the game.

Thanks

Sorry, maybe this is the wrong place to ask this or maybe its a really unique situation.

Nothing is burnt or shorted that I can see or test. The area that sparks when power is on is around R1 R3 R5 and C2 on the AS-2518-21 Bally Display board.

I have ordered more AGX 3/16A fuses to go through another round of "plug it in and watch the fun" tests, as these always blow the solenoid driver fuse.

Everything looks great on these displays including the board and the glass.

Thank you.

magnify_2020-04-10_08-18-23 (resized).jpg

magnify_2020-04-10_08-18-43 (resized).jpg

Okay today's update. I have a video of this but the site won't let me post a video. You will see the picture below of the resistor that blew out the side.

Before all of this I replaced the capacitor at C2, the six resistors at R1, R3, R5, R7, R9, and R11 w/ 100K ohm resistors. I replaced the zener diode at VR1 and checked for possible continuity issues throughout my work. The resistor that blew out is R48.

Any ideas? Too much voltage through this? Everything checks from the solenoid driver board. This is definitely a display board issue as I have one old display that works.

20200410_142135 (resized).jpg

Thank you. Yes I tested the Resistors and they checked. I also checked the Zener Diode and it checked fine. Sorry I didn't see this post before I posted todays info above.

Dan

No previous work apparent. I went through the board component by component. It's really got me stumped.

Here is the video I shot:

Thanks.