Umm, I think you might need glasses or you might need to clean 1000 layers of smoke off of the pre-pass box since they have had lights on them since they came out. ALL of them have lights. And FYI they don't all beep the same way, it depends on the scale, because mine used to beep differently depending on where I was at.
It says it has lights but they sure aren't visible in the image. I'm sure someone here is familiar with it.
They light up on the upper left where you see the 3 hash marks. You cannot see them except while they are lighting up. One thing that might be your problem is sometimes they are hard to see if the sun is glaring on the unit.