[ale] fried innards

[Alex Carver]

It's not exactly the right thing to say safety is an issue if a power 
supply delivered its maximum rating without blowing a fuse.  That's what 
you expect and that's what it is designed to do, deliver up to the max. 
  You wouldn't expect to have a wall outlet in your house claim to 
deliver 20A and then only deliver 5, right? :)

I've seen this happen a few times and it was almost always a loose 
connector (or a Molex with poorly seated pins) but in one case it was a 
fine layer of dust that became moist (high humidity in the room) and 
started to conduct current.

In any event, even just 20 amps into a 22 gauge wire is enough to light 
it up.  The event is self limiting, though, because the resistance of 
the wire climbs quickly which then regulates the short-circuit current. 
  So no fuses are gong to pop because the short is still within the 
operating parameters of the power supply.  The supply has no way of 
knowing the difference between a large current draw due to legitimate 
loads (hardware) versus a short.

If you can find the specs on the power supply, do so and see what its 
limits are.  If not, assume the power supply sustained some permanent 
damage and replace it.

On 8/6/2013 12:28, Sean Kilpatrick wrote:
> I no longer remember the brand of power supply, but I do find it
> interesting that no brand name or electrical details are visible on the
> surfaces of the PSU that I can see.
>
> Looking at the charred remains of the fried plug, I can see that both
> ground wires popped out of the plug and the 12 volt yellow wire has its
> insulation burned off for nearly 2 inches.  Yet the PSU fuse did not trip.
>
> Sean
>
> --------------------------------------------------------------------------------
>
> On Tuesday, August 06, 2013 03:11:21 pm Calvin Harrigan wrote:
>> On 8/6/2013 2:54 PM, Sean Kilpatrick wrote:
>>> Power supply is a replacement. Got burned years ago buy a cheap power
>>> supply. I no longer remember the specs on this one, but it is AT
>>> LEAST 30% larger than necessary.
>>>
>>> BUT, the box itself is more than 7 years old, and the mobo/cpu and
>>> power supply are five years old, as are the RAID-1 drives.
>>>
>>> Everything else seems to be working as it should. I'm thinking this
>>> may be the "handwriting on the wall." If that's the case, I'd better
>>> go get a lottery ticket! :)
>>>
>>> Sean
>>
>> <snip>
>> Like someone mentioned above, it was probably a loose/bad connection,
>> but still it's very odd.  Trying to imagine what could go short in A
>> DVD-ROM to allow that kind of current draw.  Filter Caps? reverse
>> voltage protection Diode?  If all is working as it was sans the DVD,
>> you're probably OK.  But for my information, what brand is the power
>> supply?
>>
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