Re: Computer turns on and then just dies

s|b <[email protected]> wrote:

> On Fri, 22 Nov 2024 00:18:24 +0800, Mr. Man-wai Chang wrote:
> 
>> CPU too hot, leading to immediate shutdown?
> 
> When it starts all fans start blowing, CPU fan included. I'm not saying
> it's impossible, but the tower was untouched after I took out the hard
> drive. No loose cables (so it seems).
>  
>> You forgot to mention the brand and model of the motherboard, and those 
>> of the power supply!
> 
> I clearly stated which motherboard it was in the OP:
> 
> ASUS F1A75
> <https://www.asus.com/supportonly/f1a75/helpdesk_manual/>
> 
> Power supply: Antec model EA-380D GREEN 380W

I didn't see mention the power consumption of that motherboard, but then
other components would add to that, like video card, drives, memory
modules, etc.  Rather than try to use some online power calculator
trying to estimate what size PSU is needed for a particular setup, I
measure the input power to the computer.

You could use a clamp A/C meter to measure how much current was flowing
into the computer on its power cord, but you need to use a splitter
adapter or shunt that separates the lines (hot and neutral) to let you
effectively put the clamp around just one wire.  Instead a kill-a-watt
meter is much easier.  You plug it into the outlet, and plug the power
cord into the meter.  That will tell you how much power is getting drawn
into the computer for all components inside, and everything attached
drawing power from the computer.

https://www.amazon.com/P3-P4400-Electricity-Usage-Monitor/dp/B00009MDBU?th=1

There are different models, and different brands.  All you might need is
a cheap model as you only want to see what the computer draws at the
time you are using it, not record high and low points or a history of
power consumption.

https://www.anandtech.com/show/3902/antec-earthwatts-ea-380d-green-380w
(use the drop-down list to read other sections of the article)

That measures the power going in.  PSUs are not 100% efficient.  Your
Antec PSU has an efficiency of 85%, at best, but that's when it was new
at a particular load.  So, whatever the kill-a-watt meter shows you
multiply by .85 for what the PSU could deliver out.  The less efficient
the PSU, the heat it generates.  I didn't bother to check if the 380W
rating was for momentary or sustained load.  Mostly when I saw 380W it
seemed too low, but then maybe your setup doesn't need much power.  At a
minimum, I'd go by the kill-a-watt meter for what you're using now, and
ignore the efficiency rating.

If I knew the mobo's max load, CPU, drives, memory, video card, and
everything else inside, and anything connected to the computer, like USB
devices that don't supply their own power, then I could figure out what
size PSU is needed.  Without all that, and to measure the actual load
versus what the specs say, I'd use a kill-a-watt meter.

If you replace the PSU, get a bigger one.  Perhaps a much bigger one,
and more efficient to run cooler.  Besides, you'll save very little
getting another 350W PSU versus a 750W PSU.  You might actually pay more
for a 350W PSU, because the manufacturers are focusing and are tooled to
produce higher wattage units.

I've bought Fortron PSUs who became FSP which sells to makers under the
brands Antec, Sparkle, OCZ, SilverStone, Thermaltake, Nexus, Zalman, and
maybe more.

350W at Newegg:
https://www.newegg.com/p/pl?d=power+supply&N=600014047%20100007657
Higher wattages:
https://www.newegg.com/p/pl?N=100007657%20600479296&d=power+supply

Might as well buy a bigger one than the same cost on a small one.