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

[zalek]

Hello, I am trying to build a new PC. After connecting all the parts,
I turned the switch on and... nothing.
I suspect that the power supply is not working, or the circuit on the
motherboard that switches the power supply on is not working.
When I flip the switch on the back of the power supply on, the
keyboard LED turns on for a second. However, when I press the major
switch, nothing happens. No fans move, and there are no noises. I
checked the major switch with an ohmmeter, and the switch seems like
it works.
I'm not sure if the power supply or the motherboard circuit that
starts the power supply isn't working.
So my question is, how can I check if the power supply is working?
Thank you very much

Zalek

 

[zalek]

Hello, I am trying to build a new PC. After connecting all the parts,
I turned the switch on and... nothing.
I suspect that the power supply is not working, or the circuit on the
motherboard that switches the power supply on is not working.
When I flip the switch on the back of the power supply on, the
keyboard LED turns on for a second. However, when I press the major
switch, nothing happens. No fans move, and there are no noises. I
checked the major switch with an ohmmeter, and the switch seems like
it works.
I'm not sure if the power supply or the motherboard circuit that
starts the power supply isn't working.
So my question is, how can I check if the power supply is working?
Thank you very much

Zalek

 

[Paul]

zalek wrote:

On Jun 19, 10:57 pm, Paul <nos...@needed.com> wrote:
zalek wrote:
Hello, I am trying to build a new PC. After connecting all the parts,
I turned the switch on and... nothing.
I suspect that the power supply is not working, or the circuit on the
motherboard that switches the power supply on is not working.
When I flip the switch on the back of the power supply on, the
keyboard LED turns on for a second. However, when I press the major
switch, nothing happens. No fans move, and there are no noises. I
checked the major switch with an ohmmeter, and the switch seems like
it works.
I'm not sure if the power supply or the motherboard circuit that
starts the power supply isn't working.
So my question is, how can I check if the power supply is working?
Thank you very much
Zalek
There is a power supply spec here, so you can see the signal names.

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2...

To start with, the power supply is split into two pieces. The +5VSB
output, is available as soon as the rear switch is turned on. The +5VSB,
in turn, flows down the main power cable and powers some motherboard
logic.

The second half of the power supply, operates the 3.3V/5V/12V/-12V
outputs. The power is "soft switched" by means of the logic level
on the PS_ON# signal. The PS_ON# signal normally is pulled to +5V,
by an internal resistor. To start the supply, PS_ON# needs to be
grounded (zero volt level).

Inside the computer, the chain of command looks like this.

Front Motherboard Grounds Main To main ATX
Power ------------ Logic runs ----- PS_ON# --------------- part of supply,
Switch on +5VSB to operate Cable fans start to spin
(momentary (latches when PS_ON# is
contact) signal) grounded

An ATX supply can be operated on the test bench.

1) Connect a dummy load to the supply. You could use a couple old
hard drives, and connect them to the Molex connectors. I have
a home made load box that I use.

2) Switch on power supply at the back.

3) Connect Green to Black with a paper clip. The fans should spin.

Then, you can use a multimeter to measure the voltages if you want.
I use a load box, drawing a light load (<100W), to help ensure
that the power supply will be regulating properly when I measure
it. I actually test new power supplies, before I use them.

Paul

Paul,
Thanks very much for answering. I understood your explanation - now I
know why the LED on the keyboard was turned on when I turned the back
switch on.

I'm not sure what you meant by "Connect Green to Black". I looked at
all the cables coming from the power supply, and I didn't see anything
green. Only yellow, red, white, black, blue, and purple.
Thanks again, I really appreciate the help.
-Zalek

If you check the formfactors.org PDF file, it has a pinout for the main
connector, with names and wire colors.

Pin Signal Color Pin Signal Color
--- ------ ----- --- ------ -----

1 +3.3VDC Orange 13 +3.3VDC Orange
[13] [+3.3 V default sense] [Brown]
2 +3.3VDC Orange 14 -12VDC Blue
3 COM Black 15 COM Black
4 +5VDC Red 16 PS_ON# Green <---
5 COM Black 17 COM Black
6 +5VDC Red 18 COM Black
7 COM Black 19 COM Black
8 PWR_OK Gray 20 Reserved N/C
9 +5VSB Purple 21 +5VDC Red
10 +12 V1DC Yellow 22 +5VDC Red
11 +12 V1DC Yellow 23 +5VDC Red
12 +3.3 VDC Orange 24 COM Black

HTH,
Paul

 

[Franc Zabkar]

On Fri, 20 Jun 2008 08:37:27 +1000, "Colin Horsley"
<horsley-spam@westnet.com.au> put finger to keyboard and composed:

"Franc Zabkar" <fzabkar@iinternode.on.net> wrote in message
news:nmpj541e473h63kl3u34dfm7oauuqvnddd@4ax.com...
I need help downloading the user manual (467KB) for an LG model
EC990SW VCR from this URL:

http://au.lge.com/products/sidemenu/list/video_vcr___PRD|MANU_manu.jhtml

I have installed the DJVU plugins for my browser (Opera), but I can't
access the appropriate file (EC990SW_NA2ALL_78B_NEW.djvu). I have also
tried Firefox. My brother who is using IE also cannot access the file.

I would be most grateful if someone could provide me with a direct
link, or send the manual to my e-mailbox.

The subject VCR is powering up with "SAFE" in the display. I suspect
this is due to a child lock.

- Franc Zabkar
--

English Owners manual (pdf) downloaded from this French site - here:-
http://mesnotices.fr/manuel-notice-mode-emploi/LG/EC990SW-_E

Click this box:-

" Télécharger le
mode d'emploi
intégral (4954 Ko)"

Page 25 to remove child lock. You need the remote. Button C.LOCK

Colin @ CATronics

Thanks.

FYI, there is an English version of that site:
http://safemanuals.com/user-guide-instructions-owner-manual/LG/EC990SW-_E

I notice that the download is 4.8MB whereas the DJVU file is only
468KB. LG Australia also emailed me a copy of the file ... in PDF
format. It was 898KB in size.

Although it's been a frustrating exercise, I can see why LG uses DJVU
on their web site.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

On 19 Giu, 00:41, Ivan <livan74_nosp...@solea.it> wrote:

Thank You for the faster reply!
So they are capacitors, the color should be yellow with brown bar (like
the other five), but this two (that have the same code of the other five
printed on) have a color that start from yellow and ens with dark brown,
so I think they are burn.
Where can I find a datasheet library for SMD components?
Thank You

They're just tantalum capacitors, what do you want to know from a
datasheet? Test them for short and for low ESR, if bad replace them.
Or just replace them in the first place.

Frank IZ8DWF

 

[bud--]

Daniel Who Wants to Know wrote:

Also I am
no expert here but I think intermittent loads can exceed the 80% rule hence
the 14 gauge cord which would normally only be good for 15 amps but is
protected by a 20 amp fuse inside the oven and a 20 amp double pole circuit
breaker in the service panel.
..

The US NEC allows about any cord of 2 conductors (not including ground)
to be used at 18A. Most (all?) cords with type starting H (hard use) can
be used at 20A.

The 80% rule is for continuous loads - over 3 hours.

--
bud--

 

[Baron]

Ian Jackson wrote:

In message <g3h492$aq5$1@registered.motzarella.org>, Baron
baron.nospam@linuxmaniac.nospam.net> writes
N_Cook wrote:

20 year old white zinc oxide ? loaded thermally conductive grease ,
somewhat crumbly and cream instead of white in the covered areas
under transistors/mica, ie not openly exposed to air.
Normal aging or long-term / repeatedly run at times over-temperature
or both

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list on
http://home.graffiti.net/diverse:graffiti.net/

That stuff dries out over time baked with the heat from the CPU.


The question is "Is the thermal conductivity reduced when the grease
dries out?"

I would have said so ! Otherwise there would be little reason to use it
in the first place. Certainly in the case of CPU to heat sink
conductivity the very thin film thickness of phase change material is
superior to the normal white filled silicone compounds. But it does
require a specific minimum temperature before it flows and thins out.
After that point the thiner the film gets the hotter it has to be
before it flows further.

Some 30 years ago, in the lab where I worked, we did some comparative
tests on the effectiveness of thermal compound. We did the tests on a
TO3 transistor bolted to a large heatsink, with a variety of
interfaces.

Thermal compounds have come a long way in 30 years.

With or without a mica washer, thermal compound seemed to make very
little difference. Surprisingly, the best conductivity seemed to be
with a thin piece of Izal toilet paper (no mica). However, although we
concluded that thermal compound was probably a very viscous form of
snake oil, it didn't seem to be consistently worse than when it wasn't
used, so we continued to use it in production.

There is a test rig described on one of the manufacturers web sites that
deals with measuring thermal conductivity. It has a number of graphs
showing different materials thermal conductivity against thickness and
pressure. Bergquist springs to mind.

--
Best Regards:
Baron.

 

[Franc Zabkar]

On Fri, 20 Jun 2008 13:40:36 GMT, bpetria@verizon.net (Brad) put
finger to keyboard and composed:

I have two WinBook XL2 laptops with Windows 98se. Most of the time, I use
them off line (off the Web) and I don't need the CPU running at full speed
(400Mhz). The problem is the noisy fan that cools the CPU. This fan is not
defective since it is noisy on both laptops and it runs constantly after a
warm up period.

I could not find anything in "Setup" or the manual that allows you to
reduce the CPU speed.

Is there a utility that would allow me to slow down the CPU, thus
reducing the heat up so the fan doesn't constantly run?

Thanks in advance, Brad

Short version:

Try CPU cooler software such as CPUidle, Rain, or Waterfall.


Long version:

FWIW, your laptop appears to be manufactured by Twinhead International
Corp. At least that's what the BIOS ID strings appear to be telling
me:

62-3500-001159-00101111-071595-440BX
62-3700-001159-00101111-071595-440BX

Here are the report files for your AMI BIOS (137 is for a laptop with
an ESS modem, 135 is for a Lucent winmodem):

http://www.users.on.net/~fzabkar/Winbook/P98WR135.RPT
http://www.users.on.net/~fzabkar/Winbook/P98WR137.RPT

There are many features in the BIOS setup which have been hidden from
the user, but I still don't see anything that may resolve your issue.
Notably, the Hardware Monitor section has no temperature, voltage, or
fan related settings.

I suggest you try CPU cooler software such as CPUidle, Rain, or
Waterfall, to name a few. IME CPUidle will drop your CPU temperature
by at least 10degC during periods of low activity, at least in a
desktop machine.

See http://www.benchtest.com/cooler.html

The specs for your laptop ...

http://www.winbookcorp.com/support/xl/xl2/xl2specs.htm

.... state that your main chipset is Intel's 443BX (north bridge) and
PIIX4e (south bridge), and that your IO chipset is National
Semiconductor's NS97338 Super I/O Controller.

The latter "manages the interface to the floppy drive, serial ports,
infrared port and parallel port." Unlike other IO chips, the NS97338
does not appear to have any hardware monitoring capability, but I'm
not sure about this (I can't find its datasheet).

The Celeron and Pentium II CPUs have an on-die thermal diode. The
443BX/PIIX4e datasheet shows this diode connected to an external
thermal sensor which is in turn connected to a "System Controller" or
to the PIIX4e south bridge via an SMBus.

I'd try a hardware monitoring program such as Motherboard Monitor 5:
http://www.softpedia.com/get/System/System-Info/Motherboard-Monitor.shtml

.... or Speedfan:
http://www.softpedia.com/get/Windows-Widgets/System-Utilities/SpeedFan-Temperature-Monitor.shtml

Everest Home Edition also has a Sensor tab under the Computer
category:

http://www.softpedia.com/get/System/System-Info/Everest-Home-Edition.shtml

One or other of the above programs may be able to tell you if you have
a software accessible temperature sensor in your machine.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Sam Goldwasser]

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).

--- 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.

 

[w_tom]

On Jun 20, 9:51 am, smlunatick <yves...@gmail.com> wrote:

You can buy apower supplyquick check tool.

That power supply tester (quick test tool) is almost useless and too
expensive. But few reasons. A defective power supply can still boot
a computer AND will be reported as good by a power supply tester.
Second, a power supply tester does not report on other failed or good
component of a power supply 'system'. Paul has discussed some parts of
that 'system'

Anything a power supply tester might do is performed by the
multimeter. A defective power supply may only be detected when supply
is under full load from a computer. Meter will do that with a
definitive answer. Power supply tester will not.

Paul has recommended jumpering the green wire to black. Another
useful solution is to measure DC voltage of purple and green wires
both before and when power switch is pressed. Everything in a power
supply 'system' is known in less than 30 seconds by those measurements
and without disconnecting things. Even the power switch is tested. No
useful report is provided by that power supply tester. Disconnecting
may create further failures.

Numbers also make possible useful replies from the better informed.
A power supply tester means that additional assistance cannot be
provided. And finally, a meter means learning how that power supply
'system' really works. Quick tester teaches nothing useful.

 

[Michael W. Ryder]

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.

 

[larry moe 'n curly]

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.

 

[zalek]

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

 

[legg]

On Fri, 20 Jun 2008 12:46:24 +0100, "N_Cook" <diverse@tcp.co.uk>
wrote:

From the 1970s / 1980s. I have an RCA databook with a lot of the big number
RCA transistor full data, but cannot find full data anywhere on these 1C..
ones , that is 1C ( one see) not IC ( India Charlie ).

Google, in half the hits seems, to show lesser data/ working subs I've put
on the net over the years.

Just repaired a 1986 HH which used , no problem with it, 1C03-C which is
presumably a voltage binning band, but thought I'd try locating some proper
info on this RCA range for when I need it in earnest.

You'll find more info prefixing the numbers properly; ie RCA1C03,
RCA1C04, ETC.

I can forward data sheets from the RCA 1977 Power Devices data book,
if you're specific about devices of interest.

For just straight one-line data summaries, check out 'Tehnomagazin'

http://tinyurl.com/6k5fhd

This combines un-proofread data, stripped from TDTowers publications
and some DATA catalogs.... and is, in turn, currently mined by a
number of 'data-sheet server' web services.

RL

 

[Dave]

I'm wanting to determin if my power supply voltages are correct on my
dead LCD TV. On my power supply board the output voltages are printed,
but since the set doesn't turn on, the only voltage I see present is 5
volts on the stand power supply pin.
I realize the power supply isn't completely turned on until the
microprocessor on my video board sends it the correct turn on pulse,
but isn't there more I can do aside from assuming the video board is
likely defective. I checked ESR on all capacitors, looked for shorted
diodes and transistors, burnt resistors, etc. What is a high failure
item on the video board which might cause this? The set doesn't come
on for even a second.
This is a Westinghouse model SK32H240S

Thanks in advance.

 

[Paul]

zalek wrote:

Hello, I am trying to build a new PC. After connecting all the parts,
I turned the switch on and... nothing.
I suspect that the power supply is not working, or the circuit on the
motherboard that switches the power supply on is not working.
When I flip the switch on the back of the power supply on, the
keyboard LED turns on for a second. However, when I press the major
switch, nothing happens. No fans move, and there are no noises. I
checked the major switch with an ohmmeter, and the switch seems like
it works.
I'm not sure if the power supply or the motherboard circuit that
starts the power supply isn't working.
So my question is, how can I check if the power supply is working?
Thank you very much

Zalek

There is a power supply spec here, so you can see the signal names.

http://www.formfactors.org/developer/specs/ATX12V_PSDG_2_2_public_br2.pdf

To start with, the power supply is split into two pieces. The +5VSB
output, is available as soon as the rear switch is turned on. The +5VSB,
in turn, flows down the main power cable and powers some motherboard
logic.

The second half of the power supply, operates the 3.3V/5V/12V/-12V
outputs. The power is "soft switched" by means of the logic level
on the PS_ON# signal. The PS_ON# signal normally is pulled to +5V,
by an internal resistor. To start the supply, PS_ON# needs to be
grounded (zero volt level).

Inside the computer, the chain of command looks like this.

Front Motherboard Grounds Main To main ATX
Power ------------ Logic runs ----- PS_ON# --------------- part of supply,
Switch on +5VSB to operate Cable fans start to spin
(momentary (latches when PS_ON# is
contact) signal) grounded

An ATX supply can be operated on the test bench.

1) Connect a dummy load to the supply. You could use a couple old
hard drives, and connect them to the Molex connectors. I have
a home made load box that I use.

2) Switch on power supply at the back.

3) Connect Green to Black with a paper clip. The fans should spin.

Then, you can use a multimeter to measure the voltages if you want.
I use a load box, drawing a light load (<100W), to help ensure
that the power supply will be regulating properly when I measure
it. I actually test new power supplies, before I use them.

Paul

 

[zalek]

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