HELP Please ! HID LIGHTING issue ***

Hey all. Need some help, please.

Getting back to growing after a hiatus. Using 600 W switchable digital ballast that takes conversion bulbs too. It’s about eight years old, but has been in proper storage for about 5 years. Vegging with the 600 W MH has been fine, but when I tried to switch to HPS, I’m getting a burning smell? I tried a conversion HPS and regular HPS. Both did it. Not cool so I took it right back out, put MH back in and no more burning smell. All three bulbs are about the same age. Two are barely used. Cleaned them with alcohol before so I know there’s nothing on the glass that’s burning off.

I’ve never experienced this. Obviously it doesn’t sound too safe to run with HPS but I need to flower. Hoping to not have to buy a new ballast if possible. Thoughts? TIA

What does the smell come from, the bulb or the ballast?

Could it be the reflector that's burning off residue making the smell due to the much greater amount of infrared present with the HPS bulb?

Hey Renfro. Thanks for answering. The smell seems to be coming either from the bulb itself or maybe the socket. The ballast is outside of tent and there is no smell coming from it.

I did wipe down the inside of reflector with alcohol although I didn’t really see anything on they are in the first place though . So weird,I’m stumped