ROFL!

It looks like most of the mess came from a previous ballast, not this one..

Correct Ash, I've repaired a couple of these Crompacks with the grey 'block' ballasts and I've seen the mess they make. Still, the son ballast really hasn't been happy, it looks to have been running very hot! I wonder how it ran the tubes and how long they lasted?

Normally it would be happier driving 110V Fluorescent tube (and possibly over 110V, as the tube is overpowered by big extent) than driving its intended 85V SON lamp. The lamp however probably didnt last long, and when it EOLd the starter welded. Then the ballast started burning up. Not for long either, such ballast would really burn to thin ash under short circuit condition in not much time. The lamp cathodes must have fused after a while and saved it

Oh my LOL, interestingly it looks surprisingly well done (ie they retained the little locking washers and all) I wonder if the old ballast was 80W Rated and they just tried to get as close as they could "wattage" wise and fitted a 70W choke? as "its only 10W under 80W" (its a shame they did not fit an 80W mercury choke! it would of be just fine LOL) defo looks like its been run for a while with a stuck starter, as Ash says it would of actually been quite happy running 5ft Tubes, the Tubes tho would not of been happy... but the ballast would not of "noticed" until the tube went EOL and the starter got stuck.

Bet that smelled nice

Ballasts like that ALWAYS smell nice..... NOT!

Yes it smelled terrible, I'm sure many of us here know and can imagine! I took the pic and launched it straight back in the skip (after removing the lamp holders lol)! I've cleaned up & saved one that wasn't far off this bad before... After washing the fixture, inside & out several times, sanding off all the blackened & blistered paint and applying fresh paint, you could still smell it.... These have 65w ballasts originally

Imagine smelling a US ballast when it goes on stuck starter, as it full of tar