Crew checking / resetting CBs can be an option / drill / consideration. However, as BOAC says, given today's poor manuals and low technical training, I would hardly describe it as a "catch all" for situations like this.
I cannot recall the earlier report and/or timings, however, for something like this I would have thought the crew in contact with Engineers on the ground, especially at home base, and they in turn, as required even with Boeing. Certainly half the time I call engineering, I am told to pull / reset CBs X, Y and Z.
AL 1:
After completing the QRH procedure and consultation with the operator's operations centre, the flight crew decided to continue the flight to Warsaw.
ex-EWR
The crew checked correctness of the procedure and then reported to the air traffic control service (ATC) inability to extend the landing gear and asked operations centre for help.
The airplane was directed to a holding zone. Around 12:25 hrs the flight crew declared EMERGENCY situation. At 12:45, after consultation with the Command Post of Air Operations Centre, it was decided to activate ground alert combat aircraft from an Air Force base to check visually the landing gear.
At 13:06 hrs the pilots of combat aircraft informed the Boeing flight crew that the all landing gear was still in the retracted position. During the flight in the holding zone the flight crew consulted their actions with the operator operations centre.
The crew carried out an attempt to extend the landing gear in the gravitational way, which ended in failure. Due to small fuel quantity and unsuccessful attempts to extend the landing gear, the crew decided to execute an emergency landing with landing gear retracted. The plane landed at Warsaw-Okecie aerodrome (EPWA), on runway 33 at 13:39.
So about 90mins from "gear won't lower" to wheels up on runway, and in consulation with their Ops for that ~90mins - having given a heads up ~8hours earlier. Certainly in my outfit, after the 8hours I think I would have had more "help" than I needed on the R/T / ACARS
Looking at the manual extracts, even if they traced the Alt Ext motor in the CB chart, this was not the CB tripped - you had to go back to the power source for that busbar.