How do I check if power supply for my PC is working? Heeeeeeeeelp!!!

zalek wrote:

> Hello, I am trying to build a new PC. After connecting all the parts,

You don't want to connect _all_ the parts and then test. You should
first connect just enough parts for a barebones system -- mobo, one
memory module, CPU, CPU cooler, graphics card (if the mobo doesn't
have built-in graphics), monitor, keyboard, power switch, reset
switch. Only after you prove that this will boot should you add more
memory, cards, drives, etc.

A common problem that prevents turning on the computer is a short
between the mobo and case, usually around one of the mounting holes or
at a corner (mobos and cases can be warped enough to let them touch --
always support the mobo near the corners, even with stick-on plastic
or rubber feet).

Make sure that the front panel power switch is connected to the
correct pins on the mobo. Not all mobos are labelled clearly for
this.

Unplug the PSU from all the computer stuff, and with it plugged into
the AC power and its rear switch turned on, measure for voltage
between a black wire and the purple wire. If you don't get something
close to +5V, the PSU is bad. Otherwise short the green wire on the
20- or 24-pin connector to any black wire (whaddya mean you don't see
a green wire??? It's between two black wires) to turn on the rest of
the PSU. While the black meter lead is connected to a black wire,
touch the red test lead to an orange (or brown) wire to check the
+3.3V DC, a red wire for the +5V, and a yellow wire for the +12V.
Don't be surprised if each voltage is off by quite a bit because
that's common when there's no load on the PSU. Also some PSUs won't
even start without a load, which can be provided by a hard drive or a
10-20 watt, 5-10 ohm resistor connected beween any black and red wires
(this resistor can get very hot).

PSU testers aren't very good and can indicate everything is OK even
when a voltage is way off. That happened when I tried a CompUSA brand
tester with a PSU whose +12V rail put out only about 10V and wouldn't
even spin the hard drive.

Thanks to everyone a lot for the suggestions.
In the meantime, I connected the motherboard with a known working
power supply, and still nothing happened. I also checked the original
power supply, as you guys suggested (connecting the green and black
wires) and the fan did start spinning. I also checked the voltage.
It showed 5.25 volts. I double checked the master switch, so it seems
that the problem is not with the power supply, but with the
motherboard.
Can you guys suggest anything I can test the motherboard with before I
return the motherboard?
Thanks a lot
-Zalek

zalek <zalekbloom@hotmail.com> writes:

> Thanks to everyone a lot for the suggestions.
> In the meantime, I connected the motherboard with a known working
> power supply, and still nothing happened. I also checked the original
> power supply, as you guys suggested (connecting the green and black
> wires) and the fan did start spinning. I also checked the voltage.
> It showed 5.25 volts. I double checked the master switch, so it seems
> that the problem is not with the power supply, but with the
> motherboard.
> Can you guys suggest anything I can test the motherboard with before I
> return the motherboard?
> Thanks a lot
> -Zalek

Double check the configuration of the motherboard - any jumpers and
other connections and that the CPU is plugged in correctly (if this
applies).

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On Jun 20, 8:28 pm, zalek <zalekbl...@hotmail.com> wrote:
> Thanks to everyone a lot for the suggestions.
> In the meantime, I connected the motherboard with a known working
> power supply, and still nothing happened. I also checked the original
> power supply, as you guys suggested (connecting the green and black
> wires) and the fan did start spinning. I also checked the voltage.
> It showed 5.25 volts. I double checked the master switch, so it seems
> that the problem is not with the power supply, but with the
> motherboard.
> Can you guys suggest anything I can test the motherboard with before I
> return the motherboard?
> Thanks a lot
> -Zalek

I just followed some suggestions, by removing the mb from the case and
connecting it to the powersupply and hard drive. again, no response.
I also noticed that one of the pins on the motherboard said RSVD_DNU.
My case comes without any wire named RSVD_DNU. I'm just curious, is
that important? And what is RSVD_DNU?
thanks again
-Zalek

zalek wrote:
> On Jun 20, 8:28 pm, zalek <zalekbl...@hotmail.com> wrote:
>> Thanks to everyone a lot for the suggestions.
>> In the meantime, I connected the motherboard with a known working
>> power supply, and still nothing happened. I also checked the original
>> power supply, as you guys suggested (connecting the green and black
>> wires) and the fan did start spinning. I also checked the voltage.
>> It showed 5.25 volts. I double checked the master switch, so it seems
>> that the problem is not with the power supply, but with the
>> motherboard.
>> Can you guys suggest anything I can test the motherboard with before I
>> return the motherboard?
>> Thanks a lot
>> -Zalek
>
> I just followed some suggestions, by removing the mb from the case and
> connecting it to the powersupply and hard drive. again, no response.
> I also noticed that one of the pins on the motherboard said RSVD_DNU.
> My case comes without any wire named RSVD_DNU. I'm just curious, is
> that important? And what is RSVD_DNU?
> thanks again
> -Zalek

Not knowing what your motherboard manufacturer and model number is I
think the pins are ReSerVeD DoNotUse.

zalek wrote:
>
> I just followed some suggestions, by removing the mb from the case and
> connecting it to the powersupply and hard drive. again, no response.
> I also noticed that one of the pins on the motherboard said RSVD_DNU.
> My case comes without any wire named RSVD_DNU. I'm just curious, is
> that important? And what is RSVD_DNU?
> thanks again
> -Zalek


Didn't you get a manual with the new motherboard?


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zalek wrote:

> Thanks to everyone a lot for the suggestions.
> In the meantime, I connected the motherboard with a known working
> power supply, and still nothing happened. I also checked the original
> power supply, as you guys suggested (connecting the green and black
> wires) and the fan did start spinning. I also checked the voltage.
> It showed 5.25 volts. I double checked the master switch, so it seems
> that the problem is not with the power supply, but with the
> motherboard.
> Can you guys suggest anything I can test the motherboard with before I
> return the motherboard?
> Thanks a lot
> -Zalek

I assume that you have plugged in the four pin plug from the PSU to the
mainboard ?

--
Best Regards:
Baron.

On Jun 20, 8:47 pm, Sam Goldwasser <s...@minus.seas.upenn.edu> wrote:
> zalek<zalekbl...@hotmail.com> writes:
> > Thanks to everyone a lot for the suggestions.
> > In the meantime, I connected the motherboard with a known working
> >powersupply, and still nothing happened. I also checked the original
> >powersupply, as you guys suggested (connecting the green and black
> > wires) and the fan did start spinning. I also checked the voltage.
> > It showed 5.25 volts. I double checked the master switch, so it seems
> > that the problem is not with thepowersupply, but with the
> > motherboard.
> > Can you guys suggest anything I can test the motherboard with before I
> > return the motherboard?
> > Thanks a lot
> > -Zalek
>
> Double check the configuration of the motherboard - any jumpers and
> other connections and that the CPU is plugged in correctly (if this
> applies).
>
> --- sam | Sci.Electronics.Repair FAQ:http://www.repairfaq.org/
> Repair | Main Table of Contents:http://www.repairfaq.org/REPAIR/
> +Lasers | Sam's Laser FAQ:http://www.repairfaq.org/sam/lasersam.htm
> | Mirror Sites:http://www.repairfaq.org/REPAIR/F_mirror.html
>
> Important: Anything sent to the email address in the message header above is
> ignored unless my full name AND either lasers or electronics is included in the
> subject line. Or, you can contact me via the Feedback Form in the FAQs.

Problem solved!!!! Thanks to all!!
The problem was that the "clear CMOS jumper" was in "Clear CMOS"
position - it should be in "normal" position.
The motherboard was A33G from PC Chips.Now my PC is working!
Other parts I used:

CPU cooler - WATER COOLER XIGMATEK|AIO-S80DP
2GB RAM - MEM 2G|PQI MAD42GUOE R
AMD CPU - CPU AMD|A64 X2 5000+ 2.6G AM2 2M R
case - CASE ATHENATECH|A3602BB.400 BK RT
DVD and HD I used from my old PC. HD had WinXP - I didn't have to
reinstall any software.

One remark - water cooler is pretty big - and takes a lot of space but
fits on the MB. Standard 4 pin ATX power connector must be connected
to MB BEFORE installing the cooler - the cooler blocks the power
connector.

Thanks again,

Zalek