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

What did musical fidelity say?

Should I just replace that board?

No.

I bet it would be a simple fix but I don’t know what I am looking at.

You don’t say

The repair shop I frequented gave me the cold shoulder for no apparent reason

Really? For no apparent reason? 

Look, like you’ve been told before, the fault is more likely than not in the protection circuitry. You have two options: 

- As @patrickalston advised, whenever the thing decides to work, leave it on. 24/7/365.

- Find a good tech and don’t antagonize them.

@devinplombier 

ok here it is: I had him repair 3 things in the last 12 months. 
he always gave an estimate and at the end he always charged $50 over the estimate. I never said a word just paid with cash.

We had a text trail of everything. This time when I texted him he responded that he didn’t know me and he is busy with his clients. I called him and told him i had been a client. He told me to contact him in 3 weeks as he was busy. 
So on Friday I did. He texted me back that he would not take any new orders.

I gave him no reason (i think, i was polite always) but who knows. 
 

My previous repair guy was famously a jerk to his clients. I put up with it as he had fixed things. Until he didn’t. He gave back my amp without opening it and charged me the inspection fee. 
This next dude seemed to be ok but fair to say i would not want to sit next to him on the plane. Arrogant and bossy personality. Next stop is LA, no other people in the used audio repair business here

re: leaving it on - i want it repaired and then sell it. I would fully disclose this issue and sell - at a loss. I feel stuck without having a good repair option.

@audphile1 they haven’t responded, I will try again.

Sell it as is for $350-$400. Someone who can fix it will buy it. 
It will cost you more in repairs. 

@audphile1 I would take $400 in a heartbeat. I just assume there will be lowball offers as if it were for parts.