Lightening and Tuner Display

You had the power protected by the surge protector, but what about your antenna?
All that static in the air gets picked up and will find the path of least resistance to ground. If your antenna doesn't have a path to ground, your tuner sure will.

You were lucky. My house took a near direct hit and it fried everything, even stuff that wasn't plugged in. My phones got reprogrammed, the CRT TVs all got magnetized to a single color and my tuner's input pretty much wasn't there no more. The most amazing damage occurred to my Apt1 amp, which wasn't even plugged in (it was behind a DPST preamp switch). When I tried to power it up a few days later, it looked like there was a sparkler inside. I grabbed it and ran it outside because I thought it was going to catch fire.

Since that episode, the mast of my FM's roof antenna is connected to an 8 foot x 5/8" copper rod driven into the earth. The antenna itself has a 300ohm to 75ohm balun transformer at it's terminals. The 75 ohm coax coming from that balun into my house is coupled to a grounding block, which is connected directly to the ground bus at my main fuse panel with a heavy gauge wire.
Grounding the block directly to the main fuse panel was done to prevent ground loop hum from developing.

Keep in mind that nothing you do will save you if you take a direct hit. Lightning has it's own mind and does what it wants. All you are doing is trying to divert static electricity to earth. And if you have a roof mounted antenna, even the wind blowing across the antenna develops a static charge.

I don't see anything surprising about that. Lightning (not "lightening," btw) produces large amounts of airborne RFI (radio frequency interference). A good illustration of that is the static that can be heard on AM radios when lightning is in the area. Obviously a tuner (FM or AM) is designed to receive very low level radio frequency signals, and to greatly amplify them. So the tuner picked up a burst of RFI at high levels, amplified it some more, and the resulting transient in the circuitry was large enough, and at high enough frequencies, to couple (perhaps via stray capacitances in the circuit board) into some of the digital circuitry in the tuner, causing the result you observed.

As long as operation subsequently returned to normal, perhaps after cycling power off and then on, I wouldn't worry about it.

Regards,
-- Al

Not sure what caused the problem, but I am sure the beer did not :)