🚀 go-pugleaf

OzzyFrank wrote:

> Idon't know how to use a multimeter, but i have seen them used
> and it doesn't look too difficult (does it?). Could you or anyone else
> please tell me how to use one, at least with a PC power supply.  Like what
> to put where, and what readings mean what. I assume if i go and get one, at
> least second hand, it would be easy enough to use for this task (testing PC
> power supplies) and would be worth the bucks invested.
> 
> Any help on this matter would be greatly appreciated.

its not that hard. ok it is the real trick is getting an atx
powersupply to run without plugging it into anything.


Pins towards you clip down
O O O O O O O O O O
O O O O O O O O O O
        [ ]

Colour chart
Y  Pu G  Bl R  Bl R  Bl Or Or
R  R  Wh Bl Bl Bl Gr Bl B  Or

Normal colours are
BL Black  - Earth 0V
R  Red    - +5V
B  Blue   - -12V
G  Grey   - Power Good
Gr Green  - Power Switch
Or Orange - +3.3V
Wh White  - -5V
Y  Yellow - +12V
P  Purple - +5V Stand By

Check the side to see if they match should be a sticker to tell you

if you look at the connector from the pin side so that the wires are
away from you and the clip is down then the power on connector is the
4th from the right on the bottom.

Use a paper cip to connect this pin to 1 of the black ones and the fan should
spin. If the fan starts then stops then you either have a dud psu or it needs
a power good signal from a motherboard.

if all goes well and the psu runs with a paper clip stuck in the connector
you can test each line by sticking the black lead of the multimeter in
a spare black lead and then probing each of the other leads with the red lead
from your multimeter (if you use an old analouge one you need to swap its leads
around to measure the negative lines)

and remember the +5V Stand By should also have 5V when the psu is off but connected
to the power.

-- 
Anthony's Law of the Workshop:
        Any tool when dropped, will roll into the least accessible
        corner of the workshop.

Corollary:
        On the way to the corner, any dropped tool will first strike
        your toes.

You only have to short two pins to get it to turn on, then you can check the
voltages to ground. Unfortunately this will not tell you if the power supply
is good or not as they really need to checked while under load.

http://www.formfactors.org/developer/specs/atx/atxspecs.htm

Motherboard Monitor (Check for temps and voltages newer boards)
http://mbm.livewiredev.com/

Lane

All power corrupts, but we need the electricity.

"OzzyFrank" <ozzyfrank@goconnect.net.au> wrote in message
news:a42sdt$a8u$2@perki.connect.com.au...
> Idon't know how to use a multimeter, but i have seen them used
> and it doesn't look too difficult (does it?). Could you or anyone else
> please tell me how to use one, at least with a PC power supply.  Like what
> to put where, and what readings mean what. I assume if i go and get one,
at
> least second hand, it would be easy enough to use for this task (testing
PC
> power supplies) and would be worth the bucks invested.
>
> Any help on this matter would be greatly appreciated.
> --
>
> OzzyFrank
>
> ��������������������������������
> Want Registry Tips and Cool Tweaks?
> ��������������������������������
> http://ozzyfrank.150m.com/C-Frank.htm
> ����������������������������������������
> Some METAL each day keeps the Demons at bay!
> ����������������������������������������
>
>

Somebody correct me if I'm wrong, but aren't the voltages measured DC 
current?  I think I had my multimeter set on AC and got erratic 
readings.  Switched to DC and got the proper readings.

"The Bvilles" <res0753w@gte.net> wrote in message
news:3C655B85.5050109@gte.net...
> Somebody correct me if I'm wrong, but aren't the voltages measured DC
> current?  I think I had my multimeter set on AC and got erratic
> readings.  Switched to DC and got the proper readings.

That would depend on if you were measuring AC voltage - as in the 240VAC
coming into the supply - or DC  - as in the 12V and 5V - outputs.  If you
have to ask, you definitely shouldn't be measuring the 240VAC!

OzzyFrank <ozzyfrank@goconnect.net.au> wrote in
message news:a42sdt$a8u$2@perki.connect.com.au...

> Idon't know how to use a multimeter, but i have seen
> them used and it doesn't look too difficult (does it?).

Its one of those things that does give some
people brain fade, but it isnt that hard.

> Could you or anyone else please tell me how
> to use one, at least with a PC power supply.
> Like what to put where, and what readings mean what.

Really depends on what you want to do.

If you have a basically working PC and just want to check that the voltages
are right, its not hard to stick the probes down beside the wires until they
contact the metal thats down in the hole a bit and measure the voltages.
The wire colors make it pretty easy to work out which voltages to expect.

You normally have one probe on one of the black wires and
then probe one of the orange wires for 3.3V, red for 5V etc.

http://www.technick.net/pinconmth_atx_power.php
http://www.technick.net/pinconmth_at_power.php

Gets more tricky if you want to check the power supply
without it being plugged into anything because the power
supply wont normally start up like that. Still doable tho.

> I assume if i go and get one, at least second hand, it would be
> easy enough to use for this task (testing PC power supplies)

Yes.

> and would be worth the bucks invested.

I dont find I do it much and I use a relatively fancy meter,
a Fluke 19, which records the max and min voltages too.
That can be handy if you suspect that the power supply
voltage is sagging in some situations like with a hard drive
spinning up. They aint that cheap tho, $100+ type money.

A multimeter is rather better than using the voltage checks that many
motherboards have now. I looked at the figures with one new system
and didnt like the numbers it was showing. The multimeter showed that the
power supply was fine and that the motherboard numbers were just odd
because of the accuracy of the pretty crude voltage measurements they do.