I have an electric stove with 50 amp 230 V line. The electronic panel has popped, and I want to surge protect the new one. My extended warranty runs out in September, and the boards are not cheap. Should iI use a whole house protector, or just for the stove circuit?

I'd go the whole house route. These guys offer a 20 year warranty. MCG Library of Datasheets,Specs & Installations for Surge Suppression,TVSS & Surge Protection

There is a lot of stuff to read there.

Although, surges may not be the reason why the board fried, but could be.

What's the make and model of the stove?

Do you know if the stove has a spark or hot surface ignitor?

I have a Frigidaire dual fuel gas top convection model glcs389fb and the panel is going out with a whimper, not a flash. It started to go black at random intervals, and a reboot fixed it. Sometimes 3 times in 10 minutes, sometimes not for a day or two. The repair guy agreed it needs a new board.

All your manuals are here FRIGIDAIRE Gallery Series GLCS389FB - 30" Slide-in Dual Fuel Range with 4.2 cu. ft. Electric Self-Cleaning Oven, EvenCook3 Element Convection System, Warming Drawer & 4 Sealed Gas Burners under info & guides.

It's a spark ignitor.

It's like Yuk! The stove doesn't even contain a ground. Wondering wheter the spark ignitor or routing could be causing the board to fry? Board looks to be about $180