HID lighting systems & troubleshooting

I had a call today about a repair for a sodium vapor lamp fixture used for a grow lamp. The guy had changed the bulb of course, and 'it still doesn't work', he said. I asked a few questions and determined that most likely, the ignitor had failed. Some gas bulbs, like sodium vapor, use an ignitor to 'ignite' or fire the circuit through the gas, and light the lamp. I recommended to him that he should replace the ignitor. Some folks call it the 'starter'.
Anyway, I'm linking you to my favorite booklet for a ton of info on gas bulbs and troubleshooting them! Great info!

http://media.hydroponics.net/productdocs/HID_Pocket_Guide.pdf