graxtax wrote:
> here is my problem, i run my new pc with a ups 800 VA, power supply
> 480 watt, 'lc power scorpio' but even with that after 3months it is dead !!!!!

> the strange thing is that the psu didn't 'die' during the time that
> pc was on, but one morning that i tried to switch it on, it did never
> switch on until i replaced the psu.

Every UPS I've checked had an elaborate surge protector built into it,
and all but the worst PSUs have an EMI filter that can also block some
surges. Unfortunately the "LC" in the name of your PSU may indicate
that it's made by Deer, which produces several brands including L&C,
Codegen, and Logic, the worst which have no EMI filters, and even the
best Deers aren't very good. One expert, JonnyGuru.com, found that a
500W Deer wouldn't even start if the initial load was over 150W,
although it could put out more power if the load was increased
gradually.

If you want very high quality at a moderate price, check out PSUs made
by Fortron-Source, which sells under brands like Fortron, Sparkle,
Trend, Hi-Q, PowerQ, Powertech (not Powertech), and sometimes
Casedge.(look for a missing screw on the side). Most of these PSUs
have model numbers starting with "FSP".

> graxtax wrote:
>
>>here is my problem, i run my new pc with a ups 800 VA, power supply
>>480 watt, 'lc power scorpio' but even with that after 3months it is dead !!!!!
>
>
>>the strange thing is that the psu didn't 'die' during the time that
>>pc was on, but one morning that i tried to switch it on, it did never
>>switch on until i replaced the psu.

What is failing? The +5vsb is *always* on, and without cooling fans
circulating air, is prone to failure in poorly designed units. If
it *is* the +5vsb that is failing (or even if it isn't), try a better
brand of PSU.

"UCLAN" <(E-Mail Removed)> wrote in message
news:HbCuf.3763$ZA5.1017@fed1read05...
>> graxtax wrote:
>>
>>>here is my problem, i run my new pc with a ups 800 VA, power supply
>>>480 watt, 'lc power scorpio' but even with that after 3months it is dead
>>>!!!!!
>>
>>
>>>the strange thing is that the psu didn't 'die' during the time that
>>>pc was on, but one morning that i tried to switch it on, it did never
>>>switch on until i replaced the psu.
>
> What is failing? The +5vsb is *always* on, and without cooling fans
> circulating air, is prone to failure in poorly designed units. If
> it *is* the +5vsb that is failing (or even if it isn't), try a better
> brand of PSU.

Not to mention that poweron is controlled by the mainboard. Could be failing
caps causing a strain on the PSU.

Finally, most PSU's put out dirtier power than you get from the outlet since
it's usually a square wave instead of a sine wave. You're protected from
power losses, but the switching is also pretty dirty.

Noozer wrote:

> Finally, most PSU's put out dirtier power than you get from the outlet since
> it's usually a square wave instead of a sine wave. You're protected from
> power losses, but the switching is also pretty dirty.

Don't you mean most UPSes puts out dirtier power? PC PSUs output DC
with less than 0.1V peak-peak AC noise.

Noozer wrote:

> Finally, most PSU's put out dirtier power than you get from the outlet since
> it's usually a square wave instead of a sine wave. You're protected from
> power losses, but the switching is also pretty dirty.

Assuming you were writing about a *UPS's* square wave, a SMPS has a
300vdc buss on its input. This should withstand a square wave just
fine. Some cheaper "auto switching" circuits (90-264 vac) *are* quite
sensitive to input waveforms, however.