So I picked up a Black Hole and it had a few LEDs in it already, I had extra so I decided to finish it up and put LEDs in the remaining areas that were missing.

On the under side of the upper playfield there are lights that illuminate when you get to the lower playfield. So I am playing a game and hit the shot to go to the lower playfield and the lights flickered a bit, then I saw and smelled smoke. I quickly shut the game off, at first I thought it might have been the lower to upper PF kicker as I had just repaired it a few days prior but everything looked good. Upon looking around I notice one of the LEDs looked slightly melted around the casing, sure enough a few had the same issue.

I decided to remove the LEDs I just placed and replace with standard bulbs and every thing works perfectly again. Did I just have a bad couple LEDs or is there something unique about that circuit? Seemed strange to me. Thoughts?

Ok, that makes sense, thanks for the insight, I figured it might be something like that, I just did pull up the manual to confirm and though someone here may have run into the same issue at some point. I ended up putting the original bulbs back in so that very well could be the case. It melted around the plastic where it meets the metal body. Thanks ForceFlow!

It is such a beautiful game, and fun too. I will definitely look up the mod. Thanks guys!