amp I bought 3 days ago not powering on - electrical engineer advice wanted

@jl35 yes, my problem is, it IS working. Once it's turned on. But it is a pretty basic function. 

Its possible you could have a cold solder joint. If you have soldering iron you could try heating some of those joints around that power switch. When it does not come on you can use a pencil with eraser and push around on the joints and see if the amp will come on. 

@dwest1023 that's a great idea. Ever since I removed the top, it has always turned on. Now I have to hope that it would not. I can never win!

Stop.  

#1.  You don’t sound qualified to fix it or able to make an informed guess.  That’s ok.  I would be too. Don;t attempt to fix, you could make it worse.  

#2.  If it’s still with the tech you don’t like, pick it up.

#3.  Did you say you’re in Orange County, CA?  Find another tech.  Contact the manufacturer to see if they can recommend a repair serviceperson.  I live in Phoenix.  You can mail it to https://www.highendrepair.com/ in Phoenix.  This is who I used.  He’s competent, but busy.  You just need patience.  (You seem inpatient, that’s ok too.  Patience takes time to develop.  These techs are busy) Welcome too the world of used audio.  Sometimes you score.  Sometimes you get scored. 

#4.  Otherwise sell it with full disclosure.  Issue sounds minor.  If I were you, I’d find a local tech.  

#5 A suggestion:  Next time pay with a credit card.  If seller takes no credit card, the seller seems sketchy, or you can’t afford to lose the money, then pass.  Another will be along shortly.   That’s true for most things.  Craigslist is sketchy++.   Shop at places  where you have recourse (e.g., TMRaudio.com)

#6.  Take internet advice that encourages you to take action (e.g., soldering on a board) with a grain of salt.  Even if you're adventurous, you may be trying to fix a problem where there is none.  

#7  If you do decide to be an adventurous shadetree technician, then, please keep us informed.  It reminds those of us who have been around for awhile of the good ol' days.

@patrickalston 

I have no desire to fix it. (I would be happy if I could, but I know my limits)

I agree with your suggestions. I hope I sound reasonable that it bugs me that it is a minor problem, and it prevents from using my only amp, so I am looking for a quick fix. I.e., I open it, watch youtube videos and try to get lucky. If only there was a lose wire  But it's clear that my best option is to find a decent repair shop. 

Credit card wasn't an option on craigslist.

Respectfully, I have had this problem for 6 weeks, I don't think I am impatient.