kind of... the problem is it can be hard to see and catch.
Basically lets imagine we have a computer that is crashing due to power loss.
Well the thing boots and starts no problem at all - you got 12v power for the most part.
The mobo will show 12v power, no problems.
But then when you try and play a game - the demand on the PSU goes up, beyond the amps it is capable of providing. You would in theory (and in practice) see a voltage drop in relation to this. BUT it only takes a second of droop for a crash. So while yes, it is possible, in practice it is incredibly difficult.
Most PSU testers use an adjustable load and precise monitoring - they are able to slowly increase the draw until they see droop. But you don't have that...