The tech has over 35 years experience, but $80 in the minimum charge per hour, with a one hour minimum.  That is OK with me, but if they bill me for (2) hours, I would say they were taking advantage.

I have the XV 212S that I bought in 1989. I am sorry to hear of your situation but definitely agree with not poking around in that amp with power to it. If a capacitor does charge, it can mean bad news quickly.
 
http://www.carvinservice.com/crg/manuals/x-amp.pdf is a link to the wiring diagram for that amp series.
 
It may also be worth contacting Carvin directly regarding authorized technicians in your area. I contacted them several months ago about mine and they responded to me the same day.

Looking at the circuit diagram, the heaters are shown the same as in my Vox.  The good news, it limits the fault possibilities to just one of three things.
1)broken track on the PCB removing power from the heaters.
2)broken connection between transformer and PCB, where the wires connect to the PCB (the two brown wires connected to H1-4 and H1-5)
3)burnt out transformer.
 
1)is easy to fix.  2)is even easier to fix (and the most likely) 3)is the most expensive, but not difficult.
 
To reiterate what Mike said,  DO NOT stick your fingers anywhere inside unless you really know what you're doing.

I just looked at the schematic. That is one complicated tube amp circuit.
 
The tone stack and reverb loop is all solid state, and there are some FETs and a couple 4558 I.C. op amps in the tube preamp section.
 
The tube heaters are wired in parallel.
 
If the diagnosis isn't made in the first 10 minutes than there is no telling how long it might take. It sure will be helpful for time savings if the tech knows this particular amp series.

ReubDot
The power light was still on, the power fuse and the speaker fuse were good. The tubes all were not glowing, the larger transformer was cold, but the smaller transformer was barely warm, with a faint hum. 

ReubDot
  When it stopped working, it first got lower in volume and distorted.  I turned it off, checked a few things on it, then turned it back on, then nothing. 

That really sounds like the 6v secondary winding breaking down.  It should be really easy for your tech guy to check for voltage from it.

 
Hey, don't go putting your hands in there.  Tube amps have supplies in the hundreds of volts, around 400 is common.  At that level, you won't be able to disconnect yourself if you touch the wrong thing.
 
When I work on the innards of my amp, I wear rubber boots standing on a rubber mat, have rubber gloves and, importantly, always keep one arm/hand behind my back.  This is just standard procedure when working with tubes.  Well at least when they're plugged in or until I've made sure the power supply caps are properly drained.
 
Not all amps will automatically bleed the big power supply caps and those can keep their charge (of 400v) indefinitely.
 
Sorry, should have warned you not to go trying to fix things yourself.  You could be dead right now.