Anatomy of a hang

[tw]

Originally Posted by busterb

My 2cents . A multimeter might, but my son and I had a bad disagreament about a power supply. The meter showed it good. But a PS tester said no go.
About 15 bucks. POWMAX atx power tester.

Tester cannot test for all that a meter does. A best power supply test is when fully under load - in the system. A power supply disconnected cannot be properly tested. Also note voltages - the numbers. Numbers are not the published ATX limits. I asked for numbers - not the subjective "power supply is good" - for this reason.

A best test of a power supply is to take numbers while multitasking is accessing every peripheral - disks, floppy, CD-Rom, network, sound card - simultaneously. Anything done by a power supply tester can be performed by the meter. Also are power supply defects that a tester cannot detect; but meter can. The power supply tester cannot test a power supply under full load - when many defects become apparent.

Then there is the rest of a power supply 'system'. It’s not just the power supply that must be tested. This also accomplished without disconnecting anything.

The down side of a meter is that these tricks must be understood. For example, what voltage would you have called 'good'?

Best way to test a power supply is when connected to system. Never start by disconnecting things until long after relevant facts have been collected. Power supply tester cannot do that. Just another reason why a meter finds problems or confirms power supply integrity so much faster. Unfortunately, too many declared a 'subject' good rather than provide those numbers. Those numbers - such as UT's numbers - tell us more about the system that has not been discussed. This is why those other voltage numbers (not yet provided) might be informative.