Had lighting strike now blower fan runs all the time and won't shut off even if thermostat wire are removed. It's a Janitrol Ninety Plus is it a bad circuit board or what?

Lightning strikes can cause major problems. I would not jump to conclusions that just the circuit board is defective. It would be best to have the unit professionally checked for all short circuits. The reason I say this is because if you replace the circuit board with a new one you might blow the new board out and the warranty on the new part will not cover a replacement for that kind of situation. Best to find out all that is wrong before starting to replace expensive parts. Also your homeowners insurance probably will cover the repair.

Control boards of all sorts are definitely sensitive to lightening strikes, so that would be the first thing I'd check. As hvac said, I would not unilaterally replace the part without pinpointing the problem. Unfortunately, control boards cannot be tested due to their complexity, so you will have to check all other possibilities before you declare it bad.