It's perfectly possible to ask VM for a box-swap, there's normally 2 ways of doing this..
1: TiVo is diagnosed faulty, and you ask the faults agent and/or any engineer nicely. They might say yes, they might say no.
2: If you've had your bundle for a while and are renegotiating your package (with an 18month new contract) then ask for a box-swap as part of the deal.
To be blunt for a moment - the only way to know for sure, is to ask VM when you call them.
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