Check before buying used

EX0800_
For everything ...;)
But seriously, ask the seller for a period of time "to check" - if it is good, I am sure of the product. Otherwise, it makes sense to think - do they slip you some nonsense that can break in a couple of days.

SonyK.
Thank you )

EX0800_
motherboard: conduits, operability of all connectors and outputs
video card: no traces of heating of the
railway: the number of slow / broken sectors, the number of errors, the operating time
Well, of course, you need to check for physical damage (bent legs at the core; melting of wires and contacts, etc.), traces of disassembly (damaged / missing seals, corresponding scratches on the bolts and on the case), the integrity of the soldering.
You can read more specifically on the Internet.

Len4ik00N
Thank you