McIntosh Tube Amp will not come on.

Yes Call McIntosh...they will help you.

I had a similar problem, I held the power button down for too long which caused the tubes to keep glowing orange.
I had a technician at my home in Brooklyn within two days to take care of it.
Call MacIntosh!

One more thought; try doing a factory reset.  You'll lose custom settings but that may do the trick.

Same. Mcintosh picked up every call unlike nearly almost every other manufacturer I called.

I've had a MA352 for three years without any issues.  I have called McIntosh support for questions and they were very helpful and responsive.  You'll speak with a tech not a call center front person.

They picked up the phone on the second ring when I needed tech support.  They were super helpful.    Definitely call them 

Some pretty ghoulish stories of their newer equipment not working with remote, slow repair service.

I would call up McIntosh, parts department, and plead for a set of new smaller tubes.  See if they can send it out to you without asking you to follow through on all the warranty BS you gotta go through.  Had a problem with small tubes and one was bad and it solved all my problems.  

Agree.  Probably just a bad tube if problems exists after resetting the unit .

Are all of the filaments in the tubes glowing? It may not be completing the warm up because of a bad tube.

Try resetting the amp. Instructions should be in the owners manual. 

If you have another like preamp level tube, swap it one at a time and hopefully it will root out the bad tube and go to ready state