'90 200 tqa fuel pump

[Nick Lawrence]

I want to confirm my diagnosis on the fuel pump.
My '90 200tqa suddenly stopped ruunning on the freeway Sunday. I did what checks I could,  still had spark and didn't find any hoses blown off.   I swapped in my spare Fuel Pump Relay and also tried the by-pass jumper I carry. Could not hear any fuel pump activity at the tank with the access cover off.
So had the car towed home.  (Many thanks to fellow lister Dave C.)
At home I externally plugged in,  to my car harness,  an armload of fuel pumps from my collection. I got some activity out of them, a buzz, squeal, or a motor sound. I suspect there are some faulty pumps in that lot.  
I hooked the my battery charger straight to the fuel pump still in the car and could hear a buzz. It did not sound like any working fuel pump I've heard.
My questions then,    Is lock-up or sieze one of the failure modes on these pumps?
                                Are there known culprits for not getting full power to the pump?

TIA
Nick (central Ohio)