Can't find usim network
iPhone 5s doesn't find usim network,
being told its xband chip is blown
and if replaced may damage cpu too.
Shall I repair or better to keep?
iOS 9.3.5
The repair to the phone might end up making the damage beyond economical repair. At this point, I'd cut my losses and just purchase a new phone. If the logic board get damaged, all you'll have is a big repair bill and an expensive paperweight.