Heartbreaker Pre Amp Tubes

I have a heartbreaker 2X12 combo that just stopped reproducing sound one day. There is a slight buzz if you turn the amp up but no guitar sound. I went through the whole Mesa Boogie troubleshooting video that's on you tube and nothing fixed the problem. All of the power tubes and the rectifier tube light up and seem to be working. Three of the pre amp tubes do not light up, but the rest do. If I switch out the pre amp tubes, the same three locations do not light up. All of the tubes work but not in the V1; V2 and V3 sockets. What else can I do to try to fix the problem?

time for a trip to the doctor...

Yep^^^
Doubt it's the valves. More than one valve going at once is rare. Pre-amp valves blowing is rare.
That they're not lighting up at all tells you there's something up with the circuit. I'd at least expect the heater to be operating. Time to get it to the amp-quacks

Where are you from? Perhaps someone here from near your area can recommend a good place to take your amp.