Electrical Dumbass-Check

[willskyfall]

I have a safety question for the electronically-minded among you; I dearly want to go through with a particular test (as I'm hungry for knowledge of the world), but I have a strong suspicion that I might set a multimeter on fire in the process.

Comments

[gdarklighter]

My advice, which I'm sure you'll find unpleasant, is not to go poking around in these things. Find the power ratings of all your equipment, and then buy a power supply that gives you a margin of safety on that number. Poking around a running piece of computer hardware without appropriate probe points is generally unwise.

[ziqueenmab]

Poking around...without appropriate probe points is generally unwise.

Obligatory baw-mah-now.

[sithjawa]

The problem with that theory is that the majority of power supply vendors actually don't advertise their power ratings as well as they should, and some even lie. Apparently it's really costly to make the higher-voltage lines not suck, so a lot of companies like to make a power supply with a really beefy 5-volt line and then go "Look, a 500 watt power supply! You should buy it!" when it won't power jack in a modern computer.

So that's easier said than done.

Last night I uninstalled a 480-watt power supply and installed my old 350-watt power supply, because the 480-watt power supply was underpowering the graphics card. So much WTF. WTF, power supply vendor, WTF?

[sithjawa]

(I knew it was underpowering the graphics card because it did so on another computer with a beefier graphics card, so when my computer crashed on playing a video and then completely refused to send picture to the monitor no matter how many times I power-cycled it, I thought 'I wonder what would happen if I switched power supplies?' It worked. I boggled.)

[ziqueenmab]

I apologize on behalf of the gimped power supply.

[ziqueenmab]

Also,

it did so on another computer with a beefier graphics card

Do we know this for certain? (I assume you're referring to my desktop here.) I suppose it's a more likely scenario than "the graphics card randomly committed seppuku one day", but I didn't think it was traced conclusively to the power supply.

[sithjawa]

Hmm, I don't know, I thought there was some other evidence towards it being the power supply, but I forget what.

[ziqueenmab]

The USB ports didn't always play nicely together and it kind of phailed at dealing with updated video drivers; the latter, at least, is still true. There's still some concern that the motherboard is just kind of elderly.

It's definitely better behaved since getting the new power supply and video card, but I don't know how much is due to the power supply alone.

[willskyfall]

Poking around a running piece of computer hardware without appropriate probe points is generally unwise.

Hm. What do you mean by "appropriate probe points?" I had intended to stick the probes of my multimeter into the sockets of one of the computer's Molex connectors; but if there's something I can jury-rig to further minimize my risk of screwing up and shocking myself (say, a male molex connector wired to pins on a breadboard), I'm willing to take the time to set it up.

I'd probably be willing to figure out the power ratings of all my equipment for future hardware purchases, but that doesn't quell my frustration that I currently don't have a good way to diagnose a failing power supply. Fried hard drives are no joke . . .