While testing my new eBay LM199, using 15v and a 7k5 resistor on the zener, only 0.7v came out. I soon realized that I had the leads plugged in backwards on my power supply.
The current limit was as low as I could get it on my crappy supply, somewhere in the range 20-40mA.
After swapping the leads I get 6.849v as can be expected. But the current is only around 1mA, obviously from the zener. The heater is drawing nothing (should be more like 8mA).
So now I don't know if I've burnt out the heater, or if it was never working anyway, due to the part being a fake.
Has anyone else here made this mistake and had the (genuine) part survive?