Jay Honeck wrote:
If he's in Class B, he's definitely screwed without a transponder.
However, it's not broken -- he's missing a piece of paperwork. If the thing
is working (and, as I said, ATC will let you know if something is amiss),
make an appointment to get the thing checked, and go fly.
A transponder is hardly a flight-critical instrument.

The Regs allow for operation within Class B without a transponder,
working or absent. Even under the Veil!