Oh yes! I've had some very exciting failures for sure in my days! Ballasts overheating and catching fire due to severe EOL situations with severely elevated mains voltage, capacitor explosions, and other fun stuff!

I guess the most spectacular fail I've had in my own personal collection is 3 shorted Philips ballasts from 1958, the fluorescent tubes literally exploded, that was extremely impressive! But not in a good way....

Back when i was a child a capacitor failed on a ballast for a 250 watt mercury lamp and it smelled up the whole house.


Parents were not amused.

Back when i was in high school a capacitor smoked up some offices with thick sticky smoke. People were looking into computers and network cabinets, completely ignoring the FL fitting on the ceiling from which smoke was visibly emerging

The capacitor was dry film type in plastic case, made in the 80s. lasted about 20 years. It was completely melted, when the janitor opened the fitting the melted plastic was stretching like chewing gum from the capacitor remains (still attached in the fitting on the ceiling) to the puddle of melted plastic that formed on the inside of the gear cover

The capacitor is wired straight across the 230V line for power factor correction, so it does not affect the operation of the lamps. Without it the 2x40W fitting pulls 0.86 line A, with it about 0.5A

In a later talk with the janitor (who worked here since the construction of the school) he told that exploding capacitors were a common occurence whenever lights were turned on back in the 1st year or so, and in many rooms he cut the capacitor out of the circuit, but not in those offices

I have since found many fittings in which the capacitors were melted in a similar way, the oldest from 1980 (as old as plastic film capacitors in plastic case go) and latest from 2010's

Just a few days ago, my 125W MV ballast cooked itself, I intervened before it caught fire. I fired up my SON-H before shower, as I always do. When I got out, my room reeked of resin, I measured the ballast temps and it was 165 degrees C. Its rating is 120 degrees.

I also found that the bulb also separated from the base, RIP my Turnhout-made SON-H 

I've had ballasts get hot enough that you can smell them a bit, but that was with F18s on F15-20 ballasts since I didn't know you can't use them together. Luckily I caught it soon enough that there were no big issues.

I've witnessed a fair few fluorescent ballasts go up in a BIG cloud of smoke ! Many years ago a classrooom in school had one release a big cloud of yellow smoke !     We left and finished class out in the courtyard !

  This one was well done when I bought the fixture : https://www.lighting-gallery.net/gallery/displayimage.php?album=5203&pos=82&pid=163404

YELLOW smoke?! How would THAT ever happen?