In the pictures you showed earlier, the lamp did look a bit the worse for wear, but if there's emitter on the electrodes they'll usually start, unless all the argon has been adsorbed, which is unlikely with newer lamps. Could well be the ballast, but I'll be interested to see how the lamp looks, and if a new lamp starts ok.

Indeed. The good news is once it stays lit, warm up and full brightness are just the same as day 1. I should hopefully have an update tomorrow afternoon EST.

WellI spoke too soon, it dropped out last night at some point and has been flashing for probably over an hour this morning. I’m going to go turn it off for now.

How old is this lamp?, putting aside the sodium for a minute, that sandy colour around the cathodes are a sign of a Philips lamp with a few 1000 hours on it already?, it would also explain why there isn’t sodium left in its dimples?

It was a year old at the time of the photo. Now it is 3 years old.

MMM POPPED IT!

It looks like the emissive coating is gone on the electrodes. The arc tube around one electrode is cracked as well as the electrode is leaning on the arc tube and the glass is bubbled where the electrode is. Not to mention some sodium has leaked out. What a failure!! The question is now how did this happen? And shall I bust open the outer envelope for closer inspection?

Quick update, the replaced lamp is still running strong with the ballast I purchased ~2018 and started running it D2D in 2019. I'm using modern PSG lamps in this and hopefully get a pic of it's condition at some point.