There might have been a short on the PC board (such as a stray wire end)
that caused the wrong voltage to get to the wrong pin of the chip. I saw
this happen once with an op amp in a kit I was assembling. When I removed
the solder blob, it worked fine.

One failure mode I observed in a NAD stereo some years ago, was
a slanted resistor. A lot of the through-hole resistors were mounted
in the upright board-space-saving orientation. One of these had been
pushed (or had drooped naturally) far enough off of the vertical, that
the wire lead running to its upper end was contacting the lead on the
component next to it. Tapping on the board elicited quite a lot of
popping and crackling from the speaker, and some sparks from the
errant resistor... quite easy to locate it!

Bending the resistor back to vertical fixed the problem, and the
receiver worked fine (and still works, last time I checked it).

--
Dave Platt AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!