Is my ozone generator dead?
 

1) I measure the ORP on 2 cups of SW in a measuring cup at 416.
2) I bubble room air through an airstone for 5 minutes with no change to the ORP
3) I pass room air through my ozone gen, thn through the airstone into the cup of SW for 5 minutes...no change to ORP.

Do you think this test confirms that my ozone generator is no longer doing anything?

Can you smell ozone

Ok I'll bite
I don't have an ozonater in my aquarium yet. But eventually want to add one.
By those tests I will say your generator is no longer working. But could it be your probe?

Have you tried cleaning the probe?
Soft toothbrush and mild soap or toothpaste is what I read.
When the probe gets dirty it apparently reads slower or not at all.

all right then.
I did a bit of reading and found out that it sometimes takes 15 to 30 min to have an accurate reading. All depending on if the probe is clean or not.
Found an article from a dubious source. Scroll down to cleaning orp probes

http://www.cannabis-world.org/cw/showthread.php?t=4008

I emailed Redsea about a problem I had once. They told me to run RO water through the unit, then blow air through it overnight to dry it out before turning it on. After cleaning it you can sure smell the ozone again.

That's interesting. I've had 2 Redsea ozonizers in the past - a 200mg with redox controller and also a 50mg basic. Both of mine stopped producing ozone. I still think they're really low quality for the price but it woulda been nice to try this possible fix. I think next time I'll buy a higher-end Sanders ozonizer because I really liked what ozone did.

Jack, care to elaborate? I have an ozone unit that isn't selling, so if there's some good reason to use it, might as well put it to use :)

Maybe PM to not hijack (more than I have)...

Read the section on ORP.

http://www.reefkeeping.com/issues/2004-05/rhf/index.php

Try adding some fresh saltwater to the tankwater in the cup, the ORP should drop then add ozone and see if it comes back up.

I have a dead Red Sea unit as well, I switched to a Sanders generator with a separate Pinpoint controller and it's been going strong for a few years now. I quit using the dryer it was kind of a PIA but I'm still using a Luft pump and a reactor.

You can smell for ozone production, so that's you basic test.
Not sure of the type of unit you have basic/plus/deluxe, but they have fuses in them that might need replacing.