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bruce6230@gmail.com · Guest

I have a generic PC with a failed PSU. The description the PSU says
lpm2-20. I need a replacement. How do I determine what replacement I
can use? My concerns are that I get the correct connector that fits the
motherboard and that the PSU fits in the case.

Brian Campbell · Guest

It is a standard ATX power supply, so it is an easy replacement. Get one
rated better than 300 watts, and you are good to go. New $20 power
supplies usually are about 420 watts which would be perfect for you.

bruce6230@gmail.com (bruce6230@gmail.com) wrote:
: I have a generic PC with a failed PSU. The description the PSU says
: lpm2-20. I need a replacement. How do I determine what replacement I
: can use? My concerns are that I get the correct connector that fits the
: motherboard and that the PSU fits in the case.

w_tom · Guest

Stop looking at price. That $20 power supply would be dumped into a
market of naive computer assmeblers at higher profit? Why? It would
be missing essential functions required in all supplies even 30 years
ago. For example, if something in a power supply fails, woud resulting
excessive voltage damage disk drive and motherboard? Maybe on supplies
missing essential functions. No for any power supply properly
designed.

Start by asking for the long list of numerical specs. If not
available, then you can assume numerous essential functions are
missing. Computer assembler who never even learned these functions are
would say, "Nonsense. The computer works. Therefore everything must
be there." They have no idea.

Just some numbers that must appear on that long list of specs:
Specification compliance: ATX 2.03 & ATX12V v1.1
Acoustics noise 25.8dBA typical at 70w, 30cm
Short circuit protection on all outputs
Over voltage protection
Over power protection
100% hi-pot test
100% burn in, high temperature cycled on/off
PFC harmonics compliance: EN61000-3-2 + A1 + A2
EMI/RFI compliance: CE, CISPR22 & FCC part 15 class B
Safety compliance: VDE, TUV, D, N, S, Fi, UL, C-UL & CB
Hold up time, full load: 16ms. typical
Efficiency; 100-120VAC and full range: >65%
Dielectric withstand, input to frame/ground: 1800VAC, 1sec.
Dielectric withstand, input to output: 1800VAC, 1sec.
Ripple/noise: 1%
MTBF, full load @ 25°C amb.: >100k hrs

Sometimes a discount supply causes other problems. Therefore a naive
computer assembler fixes it with something else - maybe a $100 UPS.
Why? He has no idea what that supply costs $25 less. He just knows he
saved money. Then he blames intermittent failures on other things -
maybe buy a UPS or other solutions. Do not be that foolish. First
demand technical (numeric) specs. If not provided, then go find a power
supply that does what supplies did even 30 years ago.

Meanwhile, what are the individual currents output on each voltage
(3.3, 5, & 12) of the original supply. Your new supply should state
(the numbers) current that meets or exceeds each number. The overall
number called watts is distorted and sometimes hyped to a higher number
because of the market they are selling to. Which watts were they
defining? You don't know and don't care. Instead look at current
numbers for each voltage.

bruce6230@gmail.com wrote:

bruce6230@gmail.com · Guest

Thanks for the reply. Bestbuy said they wanted $60 and up for theirs.
Any suggestions on where to get one in the price range you were talking
about?

lkboop · Guest

bruce6230@gmail.com wrote:

Brian Campbell · Guest

That $20 power supply exists because it is mass produced, and is good
enough for most needs. Is it inferior to the $80 PS, sure. Is it going
to blow up on you if you use it in most situations that do not require
overclocking? No. These things sell in mass quantities for a reason. They
work. Especially the new ones, they have to because of the heavy power
requirements of netburst. If you want peace of mind, waste the $80 if it
makes you feel good. However the The $20 power supply will work just
as well in most cases.

w_tom (w_tom1@usa.net) wrote:
: Stop looking at price. That $20 power supply would be dumped into a
: market of naive computer assmeblers at higher profit? Why? It would
: be missing essential functions required in all supplies even 30 years
: ago. For example, if something in a power supply fails, woud resulting
: excessive voltage damage disk drive and motherboard? Maybe on supplies
: missing essential functions. No for any power supply properly
: designed.

: Start by asking for the long list of numerical specs. If not
: available, then you can assume numerous essential functions are
: missing. Computer assembler who never even learned these functions are
: would say, "Nonsense. The computer works. Therefore everything must
: be there." They have no idea.

: Just some numbers that must appear on that long list of specs:
: Specification compliance: ATX 2.03 & ATX12V v1.1
: Acoustics noise 25.8dBA typical at 70w, 30cm
: Short circuit protection on all outputs
: Over voltage protection
: Over power protection
: 100% hi-pot test
: 100% burn in, high temperature cycled on/off
: PFC harmonics compliance: EN61000-3-2 + A1 + A2
: EMI/RFI compliance: CE, CISPR22 & FCC part 15 class B
: Safety compliance: VDE, TUV, D, N, S, Fi, UL, C-UL & CB
: Hold up time, full load: 16ms. typical
: Efficiency; 100-120VAC and full range: >65%
: Dielectric withstand, input to frame/ground: 1800VAC, 1sec.
: Dielectric withstand, input to output: 1800VAC, 1sec.
: Ripple/noise: 1%
: MTBF, full load @ 25=B0C amb.: >100k hrs

: Sometimes a discount supply causes other problems. Therefore a naive
: computer assembler fixes it with something else - maybe a $100 UPS.
: Why? He has no idea what that supply costs $25 less. He just knows he
: saved money. Then he blames intermittent failures on other things -
: maybe buy a UPS or other solutions. Do not be that foolish. First
: demand technical (numeric) specs. If not provided, then go find a power
: supply that does what supplies did even 30 years ago.

: Meanwhile, what are the individual currents output on each voltage
: (3.3, 5, & 12) of the original supply. Your new supply should state
: (the numbers) current that meets or exceeds each number. The overall
: number called watts is distorted and sometimes hyped to a higher number
: because of the market they are selling to. Which watts were they
: defining? You don't know and don't care. Instead look at current
: numbers for each voltage.

: bruce6230@gmail.com wrote:
: > I have a generic PC with a failed PSU. The description the PSU says
: > lpm2-20. I need a replacement. How do I determine what replacement I
: > can use? My concerns are that I get the correct connector that fits the
: > motherboard and that the PSU fits in the case.

bruce6230@gmail.com · Guest

Thanks for the primer on power supplies. I will take them with me when
I go shopping for a replacement.

Bruce

w_tom wrote:

Davy · Posted: Mon Jan 22, 2007 3:05 pm Post subject: Re: Power Supply Question

Here's a nifty Power Supply Wattage calculator if your interested...
http://www.journeysystems.com/power_supply_calculator.php clicking 'Start Calculator at the bottom if it's page will give you an indication of the Wattage required.

Many a PSU rating can be taken with a pinch of salt especially the 'El Cheapos'.

Davy

w_tom · Guest

The $20 power supply is the same mass produced $60 (full retail)
power supply with essential functions missing. All power supplies sell
in mass quantities. But when selling to those who don't even know what
is in a power supply, the $25 power supply is so much more profitable.
To find failure, find those who make decisions based only on price.
They will buy the $25 power supply. Failure is directly traceable to
those who somehow know; cannot be bothered to first learn facts. They
would even recommend a $25 power supply and not even ask what essential
functions are missing. They just know - reality be damned.

Informed consumer demands that long list of numerical specs. One
need not even know what those specs say. Power supplies that are
missing essential functions routinely have no such spec sheet so that
the few informed consumers cannot blow the whistle. Numerical
specifications does not say the power does DOES contain essential
functions. But a missing list of numerical specifications is necessary
to sell supplies missing essential functions.

Missing functions are sometimes obvious. Internal inspection reveals
empty locations or jumpers where parts for those functions were
installed when the same supply sells for up to $60.

Brian Campbell wrote:

Kyle · Guest

"lkboop" <lkboop@ca.rr.com> wrote in message
news:45b418e4$0$16665$4c368faf@roadrunner.com...
| bruce6230@gmail.com wrote:
| > I have a generic PC with a failed PSU. The description the PSU
says
| > lpm2-20. I need a replacement. How do I determine what replacement
I
| > can use? My concerns are that I get the correct connector that
fits the
| > motherboard and that the PSU fits in the case.
| >
| $60 for a power supply that's crazy for a starting price--Don't know
| where you are located--I like Mwave here in Southern California
| www.mwave.com or your can go to Price Watch and you can find the
lowest
| prices for any computer component in the U.S.

And I would recommend having a look at www.Newegg.com or
www.tigerdirect.com, one of these respected online retailers typically
has a quality PS on special that can be had for $35-$40 typically.

http://www.newegg.com/Product/Product.asp?Item=N82E16817153023 is
today's Newegg special, normally $36, with a $10 rebate.

--
Best regards,
Kyle

tcsenter · Guest

w_tom wrote:

Paul · Guest

bruce6230@gmail.com wrote: