MacBook (Black) No Brightness Control of Backlight

I have a 2008 MacBook (Black) and I've had some issues with the backlight not working at full brightness, it would turn off. So I would use it on a brightness setting of around half or below and it would work fine.

The main problem is that recently, I've lost all brightness settings: 0 is off, but from 1-16 they are all full brightness, which means my backlight crashes like it used to on full power.

I've tried PRAM and SMC reset to no avail. Any suggestions to why I have no brightness modulation?

Sounds like a defective inverter board. The inverter sends various voltages to the backlight in order to control the level of brightness.

Check with the folks at iFixit: The free repair manual to see what's involved in changing out the inverter board. They also sell parts. An inverter is not an expensive item, however, it's a bit involved in changing one out. Be sure to look up the step by step procedure first.