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

So the OP was trying to purchase a higher quality amp at $400 but it died after days.

I’m wondering, with $400, can one purchase a higher quantity amp AND have some reasonable assurance of decent longevity? Unless the seller indicates low hours or recap the answer seems to be no assurance.

@kennyc I bought a used amp for $800. I would not say it died. It stopped reliably turning on. When it would turn on, it would work as intended.

Pardon if off topic, but what I meant is this:

If I’m buying a used audio component, I evaluate:

• price
• Electrical compatibility 
• Current operating condition 
• age ~20years may need servicing like recap 
• case condition 
• no smoke

So I’m wondering, do other audiophiles have more effective methods or additional tips?

@kennyc no smoke what? What does it mean?

The rest

• price - GOOD
• Electrical compatibility - GOOD
• Current operating condition  - GREAT (at time of purchase)
• age ~20years may need servicing like recap  - YES
• case condition - GREAT

@parkergetdean ,

I believe he meant if it came from an environment where people smoked.

Cigars, cigarettes, joints, hookah pipes, brisket...

Not the people themselves, although I have seen that.

But that’s a story for another time.

Also, the gear itself smoking might be a potential red flag.