[Julie ann]

I have a sylvania sb10(20/20 indoor model1 100 amp max typ breaker box the main switch is broke can i buy just the switch

 

[Julie ann]

I have a sylvania breaker box in my home the msin switch is broke can i buy just that

 

[badhaircut]

Can you? Yes
Will you find it? It's hard to say because it's an obsolete breaker from my Google search. I am pretty sure that you are going to have to hire a licensed electrician with insurance to change it anyway because the wires feeding it are always live and your hydro provider has to get involved to shut the power to do the repair.

 

[joecaption]

And lot's of those old Sylvania panels where recalled years ago because of breaker failures.
They would melt without tripping.
http://inspectapedia.com/electric/GTE_Sylvania_Zinsco_Identification.php

 

[dmxtothemax]

Its hard to give a definate answer !
Generally main switchs/breakers,
are replacable if still available.
Are they available where you are ?
You would be best calling your local
Electrical supply house.
They will know.