I respectfully disagree with Mark in post #12 and agree with W8RMH in post #4. I don't believe Amazon is purposely sending out bad stuff, but I bought a couple of Whistler scanners from them (1040 and 1065) about a year ago and they were beat up, scratched, and the manuals with both had been underlined with a red marker.
I'm sure someone returned those, Amazon just put them in the wrong bin, and out they went to me. Also some reports on RRDB a while back of people buying new scanners and getting 10 year old scanners in the box. Obviously, someone switched them, returned the old scanner, and out they went again.
Do you think the people at Amazon know the difference between a BCD536HP and BC780XLT, or between a TRX-2 and BCD996T. I highly doubt it. I suspect the 436HP and TRX-1 that Mike (OP) have (or had) belonged to someone else, a problem was noted, they were returned, and Amazon put them in the wrong bin.
Who knows these days, maybe Amazon sends the same stuff out two or three times, and if it comes back the 2nd or 3rd time, then it goes in the defective bin.
Anyway, Amazon is a great source for all kinds of things, especially connectors, USB cables, serial port adapters, etc, that you can't seem to find these days at any consumer electronic stores, the few that are left. But a $500 dollar scanner, forget it. The Ham Station, HRO, Scanner Master, or any other known dealer is a much better bet, even if the cost is a bit higher.
I like the Ham Station because Jeff is into scanners and shares the same enthusiasm for scanning as many on these forums. If you have a problem with Scanner Master, Rich Carlson N9JIG will help you out. No one at Amazon is going to know diddly-squat.