Ouch!!!
I´m attaching DB750 schematic, which should be close enough for troubleshooting.
It´s a BEAST of an amp, but specially has a *very* complex self protection section, see page 5 , which complicates servicing.
In principle, since it happened after normal transport but not rolling downstairs or similar, most probable is that some of the myriad connectors and cable harnesses unplugged, or anything seated on a socket (tubes or relays) did the same.
With amp OFF and unplugged from mains for 1 hour, pull and firmly reseat each and every cable harness connector, any plug in sub board (if any), relays (if in sockets), etc., then plug into mains, no instrument or speaker connected, all controls set to 0, pray a little and turn it on.
There´s a high probability it starts normally.
If not, troubleshooting is complicated, maybe the shortest path is to ship it back to Aguilar factory, freight will be expensive but you have a guarantee it will be solved.
Not so sure about an "independent" Tech, if anything because Factory will not help him or sell him parts if needed.
Just as a side note: when "outside" North America or Europe, or far away as we are here in Argentina, I always suggest Musicians to buy less glamorous and simpler amplifiers, in this case suggest older Peavey or Ampeg, not the latest Class D versions either.
Popular, easy to find schematics, lots of Techs worked with them so many can offer advice, Mother Companies take care of users , keep replacement parts (in case of Peavey, for up to 30 years) , you feel backed up.
In other examples, you are not.
Won´t name names, but some amplifiers have to be sent back to Mother Company to Italy, Sweden , Denmark or good old USA to be serviced at original factory .
Consider this for your next purchase.
