What blows out in a C band LNB?

[xibalban]

So,

There was a stupid incident of injection of 440 V AC onto our mains (which normally is 220 V only). The high voltage jumped through the gaps on the common room switch (16 A SPST switch), and managed to damage my TV, and set-top-box connected to the common mains 3 pin socket.

The TV was saved, as the HRC fuse blew and I replaced it. The STB burned with a bang and I replaced its circuit board. But, the damage was more. The surge went up through the Coaxial Cable and damaged my 4x1 DiSEqC Switch (no visible burns though) and ran up till all my 4 C Band LNBs connected to the DiSEqC switch and jacked them too. None of the LNBs work, and when I pried one of them open, there is no visible damage (like burns, etc.) The circuit board, is extracted and photographed as attached:

I could identify the IC as LM339 and the Transistor (BTW, that's where the coaxial cable seems to be connected) reads vaguely 883.

My question is, can the circuit be repaired? Which component usually blows up if there's a power surge through the coaxial cable?

[rg58]

LNCs are very sensitive devices as they use special low noise GaAs-FET or HEMT transistors on their inputs for the weak satellite signal, followed by a broadband MMIC amplifier to drive the signal down the cable. Changing those ones is very difficult, hard to get and expensive. The rest might be possible to replace, but I believe it is not worth a repair. Sorry to say, but you might have to get a new one.

[xibalban]

LNCs are very sensitive devices as they use special low noise GaAs-FET or HEMT transistors on their inputs for the weak satellite signal, followed by a broadband MMIC amplifier to drive the signal down the cable. Changing those ones is very difficult, hard to get and expensive. The rest might be possible to replace, but I believe it is not worth a repair. Sorry to say, but you might have to get a new one.

Thanks for the response. I called up the LBN manufacturer and enquired if they sell PCB only as I had the metal casing already. They said, NO. I have no choice other than buying a new LNB.