On Tuesday, February 21, 2017 08:37:11 AM Dan Purgert wrote: > GiaThnYgeia wrote: ... > > Never a good idea, there are cheap tools of measuring current, a short > > can blow a good power source/transformer. How do you check industrial 3 > > phase 440V, just ground it with a train rail see if there are any sparks. > > Hint - that's exactly what the on switch does. > > Granted we're talking 5V with a max current of 1-2mA or somesuch, and not > 440VAC. It's no more dangerous than touching the red and black leads of > a battery holder[1] to a small lightbulb (such as used in a flashlight, > model car, etc.) or a LED to verify it works / you have polarity right. > Actually, given that it's limited to 1-2mA, it's probably SAFER than > said battery-holder (since most dry-cell batteries can supply 2A > current, albeit for a very short amount of time).
I agree that giving advice like touching the switch pins with a screwdriver is a bad idea--among other things, somebody might "learn" from that and try it under more dangerous circumstances. (And, do you remember the days when computer on-off switches controlled the 120 VAC to the power supply? Granted, you could do the same thing semi-safely, but make sure the screwdriver blade doesn't touch the grounded chassis or some other grounded piece of metal work--those switches always seemed to be very inaccessible.) > And to ensure the motherboard isn't the culprit, you can always connect > the PS_ON (green) wire (in the 20/24-pin connector)any GND pin (black > wire) with a short length of wire. In case it is not clear, you do this by unplugging the 20/24 pin cable from the power supply and then note if the fan starts running. (Unless I misunderstand what Dan is suggesting.