I upgraded firmware to 2.2.42 and lost WMAQ NBC 5

I was getting error signal weak on NBC5 and it has worked fine for close to a year, I updated the firmware and now NBC 5 wont even come up on the channel scan. I am less than 20 miles from tower, my antenna is pointed directly at tower with max signal on my signal meter but it is no longer picking up that channel. Why? Ideas?

Is this a Tablo 4gen or legacy.? Do you have an amplifier on your antenna? The 4gen has an internal amplifier, so if you have an external amp also, you could be overdriving the signal. Try toggling the amp on and off and see what happens.

I have the quad legacy model with and external antenna. I installed a signal amplifier on the incoming line from antenna and was able to acquire the NBC back along with 20+ other channels. Thanks for your help.