does anyone know if the ballast for the light is replaceable on the IQ 2000
1998 tiger river spa siberian model L

Sure it is...you just need to remove 2 screws and the flag terminals from the board. It is located on the back side of the IQ2000.

thanks
I'll check it out.

Are you sure you need to replace the ballast? Try a new bulb first, if it works initially, but then goes right out again, it's not the ballast, there a little doodad that needs to be removed from the control box.

I put a new bulb in and it worked great, two days later it wont turn on.
i tried the new ballast but nothing happened, where do you get one of these doodads that you are talking about? and where is it located?

You don't get the doodad, you remove it. Here's a low res phone pic. Just pop off this thing. Don't pop off the coil under it, or anything else. Then, replace the bulb again, and it will be fine. This is only to be removed on TR spas with flourescent bulbs, not for any Hot Spring bulbs.