new system bootup woes

"Paul" wrote in message
...
Adam wrote:
"mike" wrote in message
...
On 12/16/2014 10:20 PM, Jonathan N. Little wrote:
Adam wrote:
Host OS: Ubuntu Desktop 12.04 LTS
Motherboard: ASUS Sabertooth 990FX AM3+ AMD SATA 6Gb/s USB 3.0 ATX
Computer Case: Antec Three Hundred ATX Mid Tower
Power Supply: OCZ ModXStream Pro 600W Modular


I am having trouble with power to brand new system.

After talking with OCZ tech support and doing a simple test,
we were able to get the PS fan to spin-up. OCZ Tech support concludes
that
this is a strong indication that the PS is functional.

Next, I suspect that the Antec case's I/O panel wiring to mobo pins
may
be the culprit. The wiring seems fine to me but still no power.
Maybe a loose connection? How to make a stronger connection?


If the system powers up to where the power supply fan runs then start
looking a the motherboard. Any post codes? Indicator lights on
motherboard? Reseat RAM. Check CPU, remove all cards except video (if
not using onboard) and see if it posts then.


What does your voltmeter say?

Oh boy, that's new to me. I'll see if I can find any "how to" links on
troubleshooting with a voltmeter.

Now you understand why I "bench test" on the kitchen table first,
before putting the system in the computer case.

You don't absolutely need *any* wiring to the front panel at all,
for a bench test. But what I do instead, is keep a push button switch
with two connector pins on the end, which slide over the PWR and Ground
pin pair. That's for turning the system on. I can also slip a screwdriver
tip between those two pins, to bridge them and start the system. That
requires a good deal of care and dexterity, and is only
practical when the motherboard is sitting on the kitchen table.

http://i61.tinypic.com/28bgwf9.gif

On the picture there, you can see that header has a "dangerous pair"
in the SPKR pin area. Don't bridge that +5V pin if you can possibly
manage it, to any adjacent Ground pins. It's another one of those
situations where there may be no protective fuse in the path.

*******

In the past, some Antecs have had wiring errors in USB or Firewire
cables (that's a 2x5 on the motherboard end, leading to a front
panel mounted connector). So I would not hook up the front panel I/O
wiring at all. On a couple Antec cases here (I have at least three
of them), I use the multimeter, set to ohms range, to verify the cable
wiring is correct. It's just easier to *not* use Antec front wiring, than
be bothered to do that. None of my Antec front USB ports are hooked up,
for this reason. I'm too lazy to correct the errors by moving the
pins around in the 2x5 end.

*******


Okay, I have disconnected the Antec case's front I/O panel USB connector.


I take it, OCZ had you do the "unconnected supply" test ?

For that one, you bridge PS_ON# to GND on the ATX cable.

Bringing the logic level low on PS_ON# is what makes
the supply fan spin, and the main supply section to function.
On page 37 here, that would be the green PS_ON# wire, to an
adjacent black GND wire. Some people recommend connecting
a dummy load to the supply, in the form of an old (scratch)
hard drive or something that draws a similar small amount
of power.

http://www.formfactors.org/developer...public_br2.pdf

*******


Yes, the "unconnected supply" test sounds like what I performed.
Short the green wire to a black/gnd wire in order to test that
the PS fan spins.


This is a simplified model of the ATX supply. There are two
power generation circuits, and +5VSB is separate from the rest.

AC Input ------+--- +5VSB circuit
|
+--- +3.3/5.0/12V main section

When you switch the supply on at the back, the +5VSB starts to
produce power immediately. The fan will not be spinning at
this point. The +5VSB provides 2 to 3 amps max, and is
used as a supervisory voltage, amongst other uses. The
ATX power supply is convection cooled at this point, when
removing heat from the +5VSB circuit. Due to the modest
capacity of the +5VSB, it doesn't get too warm.

When the ATX power supply main cable has PS_ON# and GND
brought together, that grounds the pullup resistor on
PS_ON#. Normally, with a voltmeter, you'd see 5 volts
level on PS_ON#, and it's when that level is grounded
that the supply runs. The fan begins to spin, and the
main voltages begin to be produced. The motherboard
would be starting to POST at this point. The case
fans would be spinning.

If you attempt to start an ATX supply, and you see
the PSU fan "twitch" about a half inch of rotation,
that means the supply tried to start, but encountered
a serious short circuit (current overload) on the outputs.
To protect against burning any cables, the ATX supply
has latched off. Normally, you'd need to switch off at
the back, wait 30 seconds, switch on again, to make
another attempt to start the system. The reason the
supply "twitches", is the overcurrent is disabled
for the first 35 milliseconds, until the PSU has had
a chance to charge the output capacitors, and that
allows the fans to receive current for 35 milliseconds.
The fan blades can only "twitch" in such a short time
frame. If the "serious short" is present, when the
overcurrent detection is enabled at 35 milliseconds,
the power supply immediately shuts off the main section.

(The reason you wait 30 seconds, is to give any inrush
limiter time to cool off.)

In this diagram, the +5VSB is used to power the control
circuits. The motherboard logic "latches" the momentary
logic low level from the front panel switch, and drives
out a "steady" 0.0V level on PSON#. And that's what is
used to control the ATX supply.

+5VSB (0.0V level +5VSB
| means "run please") |
Pullup \_ Pullup
Resistor \ Resistor
| PS_ON# |
PWR X----+---- Motherboard ---- Open -------------------+- ...
control
/ logic Collector (to of
main
| GND X----+ Driver ATX + PSU
| | supply) |
section
(Front GND GND
Panel
Switch - normally open, momentarily close to operate)

By removing any USB panel header or Firewire panel header wiring
from the front panel to the motherboard, you're removing
a possible place for electrical shorts to happen. Wiring
up the PWR button from the front of the case (two wire twisted
pair labeled PWR and GND), gives you enough control to turn
the system on and off.

*******


Okay, the Antec case's front I/O panel USB connector is no longer connected.


On an Asus motherboard, there is a green LED which is wired
in such a way as to monitor for +5VSB. If the ATX PSU is supplying
+5VSB, and the main PSU cable is wired up, the green LED should
be glowing. And the LED should not flicker. It should be
a solid level for the entire time that the switch on the
back of the ATX supply is in the ON position. Asus provides
the LED, to tell you when it is safe to work inside the PC.
The LED must be completely extinguished, before you
work on RAM DIMMs or pull PCI Express cards, that
sort of thing. It takes up to 30 seconds for +5VSB to
drain, after the ATX PSU is switched off.

Paul

Okay, sounds like what the mobo manual calls the standby power (SB_PWR) LED,
which lights up no problem whenever mobo is connected to PS so far.

VanguardLH wrote:
Paul wrote:

When debugging a power problem, at system startup
the components don't draw "max power". Even a modest
power supply, mistakenly connected to a high power system load,
should get you to the BIOS screen.

I've seen where an underpowered or weak PSU (they get limp over time)
won't power up a system (to the POST screen) that is minimally
configured until the HDD is disconnected. Too much power draw on a weak
PSU means no boot or unreliable boot despite the PSU's fans will spin.

This is true. The very first PC I got (late to the PC game),
the power supply on that failed in the limp state. The power
supply still operates, and can give enough power to run a
12V @ 0.1amp fan. Any more load than that, and the voltage
falls off pretty rapidly. But that supply also had a lot of
years of usage on it, so the failure mode isn't a complete
surprise.

Which reminds me, I took a trip to the recycler last week,
and I forgot to load that thing into the car :-)

Paul

"VanguardLH" wrote in message
...
Paul wrote:

You don't absolutely need *any* wiring to the front panel at all,
for a bench test. But what I do instead, is keep a push button switch
with two connector pins on the end, which slide over the PWR and Ground
pin pair. That's for turning the system on. I can also slip a screwdriver
tip between those two pins, to bridge them and start the system. That
requires a good deal of care and dexterity, and is only
practical when the motherboard is sitting on the kitchen table.

If shorting the PWR pins on the onboard front-panel pins doesn't work,
and to test the PSU is okay, bypass the onboard logic for soft power up
of the ATX PSU. Short the PS_ON line (green wi pin 16 on a 24 power
connector, pin 14 on a 20-pin connector) to a ground line (black wire).
See pinout at http://www.smpspowersupply.com/connector_atx_pinout.GIF.
The signal floats high but the onboard logic pulls that line low to tell
the PSU to power up. Shorting it to ground effects the same pull to low
state. If done while the PSU is disconnected from the mobo, some PSUs
won't power up until they sense a load, so attach an HDD.

Front panel power switches can go bad or be defective so the PWR pin
short is a good test; however, if that doesn't work, make sure the PSU
will come up if its PS_ON line is pulled low.

Thanks, the "unconnected supply" test (shorting the green wire to black/gnd
wire) passed since
the PS fan spins.

On a side note, the Antec case's front panel power switches seem really
flimsy so
I may need to go buy a switch button for PWR-GND pins. Any recommendations?

Adam wrote:


On an Asus motherboard, there is a green LED which is wired
in such a way as to monitor for +5VSB. If the ATX PSU is supplying
+5VSB, and the main PSU cable is wired up, the green LED should
be glowing. And the LED should not flicker. It should be
a solid level for the entire time that the switch on the
back of the ATX supply is in the ON position. Asus provides
the LED, to tell you when it is safe to work inside the PC.
The LED must be completely extinguished, before you
work on RAM DIMMs or pull PCI Express cards, that
sort of thing. It takes up to 30 seconds for +5VSB to
drain, after the ATX PSU is switched off.

Paul

Okay, sounds like what the mobo manual calls the standby power (SB_PWR) LED,
which lights up no problem whenever mobo is connected to PS so far.

Make sure any USB loads are disconnected. No iPod or iPad charging.
Disconnect the memory card reader. The purpose of doing that,
is to try to get as much +5VSB power available as possible.

You would check the voltage level on the +5VSB wire of the PSU.
With a multimeter set to the 20V full scale range, probe pin 9 (purple)
and measure with respect to ground. I use an alligator clip on the
multimeter black lead, and clip to a ground screw on the back of the PC
to establish the black wire potential. Then, I have one hand free to work
on probing with the red multimeter wire.

When the 24 pin PSU connector is installed into the motherboard, there
is a little clearance where the PSU wire goes into the back of the connector.
It's possible to put the tip of the red lead, between the wire and the
plastic connector shell. And make electrical contact. That's how you
measure the voltage on the purple wire, while the system is in use.

The PS_ON# wire, when the computer isn't running, should be pulled
high (to the same voltage level as the purple wire you just checked).
So now you've measured green. If the voltage is low (and you haven't
attempted to turn on the PC yet), then the open collector motherboard
driver isn't working right.

But you've seen the green LED, which is a first order indicator
that it's working a bit on +5VSB. If the LED was dim, you'd suspect
PSU trouble.

Now comes the fun test. Connect PWR to GND on the motherboard
panel header (a momentary touch is enough). The fans should
all start to spin. If they don't, and you really think you were
successful in grounding the PWR pin, now you go back and check
the PS_ON# green wire. It should drop to 0.4V to 0.7V or so.
That is the open collector motherboard driver, pulling the
line low and asking the power supply to turn on the main rails.

If the PS_ON# signal is still high ( greater than +2.0V ), then
the motherboard needs to be replaced (under warranty). If the
PS_ON# wire is 0.4V like it is supposed to be, and the PSU
doesn't react, replace the PSU. You've already done the
"unconnected supply" test, so somehow I don't expect the
problem to be an un-reactive PSU. It's more likely at this
point, to be a motherboard open collector driver that
can't pull PS_ON# low. (Or as Vanguard mentioned, a defective
front panel switch.)

What's strange about this whole thing, is the failure frequency
of this interface. I just don't get it. The motherboard has
a couple thousand high tech electrical signals, and that damn
low tech signal is the one that fails. They must cover that
pin with the two minute functional test at the factory (or their
test bench wouldn't turn on), so they must be able to verify
PS_ON# drives low, by virtue that the woman doing the testing
is able to complete all her tests (in the two minutes allocated).
(There was a video available, of that testing process at Asus.
That's how I know it's a woman :-) )

Asus used to produce anywhere from 3 million to 5 million motherboards
per month, so that 2 minute functional test is one expensive test to
carry out. But it's essential. They can do boundary scan structural
testing until the cows come home, but a functional test covers things
like that PS_ON# signal. Just to prove the motherboard works. It's
really a final acceptance test, to make sure as many duff motherboards
don't get put into cardboard boxes, as possible.

So we're basically checking a couple voltages here. To fault isolate
and tell whether the PSU or the motherboard should be replaced.
The purple wire runs the Asus green motherboard LED. We want to
check that it reads 5.0V +/- 5% or so. The PS_ON# signal, when the
system is off, should also be 5V (same voltage as purple). When the
momentary switch on the front is pressed, the PS_ON# voltage
drops. And using your multimeter on the green wire, verifies it
dropped to around 0.4V or so. It won't drop to zero, because the
driver doesn't go all the way to exactly zero. It just has to pull
low enough, to be well below the 1.5V to 2.0V threshold on the
thing receiving the signal.

+5VSB (0.0V level +5VSB
| means "run please") |
Pullup \_ Pullup
Resistor \ Resistor
| PS_ON# |
PWR X----+---- Motherboard ---- Open -------------------+- ... control
/ logic Collector (to of main
| GND X----+ Driver ATX + PSU
| | supply) | section
(Front GND GND
Panel
Switch - normally open, momentarily close to operate)

On some supplies, if the PS_ON# signal rides around 1.5V to 2.0V
(in other words, right on the threshold), the power supply actually
comes on half-way. This leads to weak rails, and an inability to supply
full load current. Apparently, the on-off control isn't as "digital"
as it should be. So if the supply appears limp, sometimes it's not
actually the supply. And this is an important reason to be
measuring the green wire, and that it's driven to 0.4V or less.
Otherwise, the wrong component could get the blame. And this
whole procedure is for "fault isolation", identifying the defective
part.

Paul

"Jonathan N. Little" wrote in message
...
Adam wrote:
"Edmund" wrote in message
...
On Tue, 16 Dec 2014 22:00:51 -0800, Adam wrote:

Host OS: Ubuntu Desktop 12.04 LTS Motherboard: ASUS Sabertooth
990FX AM3+ AMD SATA 6Gb/s USB 3.0 ATX Computer Case: Antec Three
Hundred ATX Mid Tower Power Supply: OCZ ModXStream Pro 600W Modular


I am having trouble with power to brand new system.

After talking with OCZ tech support and doing a simple test,
we were able to get the PS fan to spin-up. OCZ Tech support concludes
that this is a strong indication that the PS is functional.

Next, I suspect that the Antec case's I/O panel wiring to mobo pins may
be the culprit. The wiring seems fine to me but still no power.
Maybe a loose connection? How to make a stronger connection?

Any ideas?

Normally there are some leds on the mainboard giving info about its
status. Sometimes this is found in a manual.....
Stronger connection??? not likely the problem.

Edmund


Thanks, yep, I was looking through the mobo manual and
there are CPU_LED, DRAM_LED/MemOK button,
VGA_LED (which is completely blocked once video card is connected ), etc.
Will be checking those out later.


Also most motherboards have a speaker pins on the front panel header, and
they include a little speaker dongle that if you connect it you can get
post beep codes that can help.


The Antec case did not come with a 4-pin mobo speaker for
post beep codes so I bought one. But, the orientation is not clear.
There are only two actual wires (one red and one black separated by two
blanks/GND?).
Connecting the black to "Speaker" pin and the red to "+5V" pin makes
orientation consistent with the other connectors. Hope my guess is right.
:-)


As someone else mentioned did the CPU fan start? LED on motherboard light
up? HD spin up? Monitor get a signal or NO SIGNAL message?


No, I did not get CPU fan to spin yet. Still cannot PWR ON the system.
Antec case's POWER button seems flimsy. Will try a switch button instead.
Yes, standby power (SB_PWR) LED lights up no problem whenever mobo
connected.
Can't see VGA_LED once video card is connected. Poor LED placement on mobo.
Not sure about the other tiny LEDs yet. Haven't been able to power ON the
system.
No, no drives (HDD, DVDs, etc.) are connected yet. Just the bare minimum.
No, I haven't gotten to video signal yet. Can't power ON yet.

I shall never take fans spinning for granted again. :-)


As I said you should try with minimal connections...remove everything
except video and the connection to the "pwr sw" pins on the front header.
This narrows your search.


OCZ tech support made sure that I disconnect everything except for
one HDD yesterday. I've reconnected the video card.


--
Take care,

Jonathan
-------------------
LITTLE WORKS STUDIO
http://www.LittleWorksStudio.com

"Jonathan N. Little" wrote in message
...
Adam wrote:
Host OS: Ubuntu Desktop 12.04 LTS
Motherboard: ASUS Sabertooth 990FX AM3+ AMD SATA 6Gb/s USB 3.0 ATX
Computer Case: Antec Three Hundred ATX Mid Tower
Power Supply: OCZ ModXStream Pro 600W Modular


I am having trouble with power to brand new system.

After talking with OCZ tech support and doing a simple test,
we were able to get the PS fan to spin-up. OCZ Tech support concludes
that
this is a strong indication that the PS is functional.

Next, I suspect that the Antec case's I/O panel wiring to mobo pins may
be the culprit. The wiring seems fine to me but still no power.
Maybe a loose connection? How to make a stronger connection?


If the system powers up to where the power supply fan runs then start
looking a the motherboard. Any post codes? Indicator lights on
motherboard? Reseat RAM. Check CPU, remove all cards except video (if not
using onboard) and see if it posts then.


No, not the system, literally the only device connected to
the power supply was just a HDD (no mobo or anything else).
OCZ tech support just wanted to see if the PS fan will spin-up, which it
did.

Next, I connected the mobo with CPU and RAM (but no video card).
OCZ tech support didn't want the video card connected.
Then, the PS fan no longer spins.



--
Take care,

Jonathan
-------------------
LITTLE WORKS STUDIO
http://www.LittleWorksStudio.com

"Dustin" wrote in message
33.145...
"Adam" Wed,
17 Dec 2014 07:45:38 GMT in alt.comp.hardware.pc-homebuilt, wrote the
following message:

"mike" wrote in message
...
On 12/16/2014 10:20 PM, Jonathan N. Little wrote:
Adam wrote:
Host OS: Ubuntu Desktop 12.04 LTS
Motherboard: ASUS Sabertooth 990FX AM3+ AMD SATA 6Gb/s USB
3.0 ATX Computer Case: Antec Three Hundred ATX Mid Tower
Power Supply: OCZ ModXStream Pro 600W Modular


I am having trouble with power to brand new system.

After talking with OCZ tech support and doing a simple test,
we were able to get the PS fan to spin-up. OCZ Tech support
concludes that
this is a strong indication that the PS is functional.

Next, I suspect that the Antec case's I/O panel wiring to mobo
pins may be the culprit. The wiring seems fine to me but still
no power. Maybe a loose connection? How to make a stronger
connection?



If the system powers up to where the power supply fan runs then
start looking a the motherboard. Any post codes? Indicator lights
on motherboard? Reseat RAM. Check CPU, remove all cards except
video (if not using onboard) and see if it posts then.


What does your voltmeter say?

Oh boy, that's new to me. I'll see if I can find any "how to"
links on troubleshooting with a voltmeter.

huh? Oi...

You really should do that when you have the chance. it's a handy tool
and skill to have.


Yes, sir.



--
My truck does not leak. It's just marking its territory!

On 12/17/2014 10:53 AM, Adam wrote:
"DecadentLinuxUserNumeroUno" wrote in message
...

On Tue, 16 Dec 2014 23:45:38 -0800, "Adam" Gave us:


"mike" wrote in message
...
On 12/16/2014 10:20 PM, Jonathan N. Little wrote:
Adam wrote:
Host OS: Ubuntu Desktop 12.04 LTS
Motherboard: ASUS Sabertooth 990FX AM3+ AMD SATA 6Gb/s USB 3.0 ATX
Computer Case: Antec Three Hundred ATX Mid Tower
Power Supply: OCZ ModXStream Pro 600W Modular


I am having trouble with power to brand new system.

After talking with OCZ tech support and doing a simple test,
we were able to get the PS fan to spin-up. OCZ Tech support concludes
that
this is a strong indication that the PS is functional.

Next, I suspect that the Antec case's I/O panel wiring to mobo pins
may
be the culprit. The wiring seems fine to me but still no power.
Maybe a loose connection? How to make a stronger connection?



If the system powers up to where the power supply fan runs then start
looking a the motherboard. Any post codes? Indicator lights on
motherboard? Reseat RAM. Check CPU, remove all cards except video (if
not using onboard) and see if it posts then.


What does your voltmeter say?

Oh boy, that's new to me. I'll see if I can find any "how to" links on
troubleshooting with a voltmeter.


You can buy a multi PS tester for PCs at Amazon or other popular
retailer that costs about $7 to $15 and you hook you disconnected PS
cable to it, and it gives voltages for all the ATX supply rails in the
spec.

Easy greasy...

http://www.amazon.com/Coolmax-Power-.../dp/B002R06PGE

http://www.amazon.com/Coolmax-PS-228.../dp/B004ZPB546

Halfway down the page on the second one is a whole row of them to
compare.


Thanks, added it to my wish list just in time for Santa. :-)


If you intend to build computers, you simply must have a multimeter.
Depending on where you live and what coupon flyers you get, Harbor
Freight will give you a voltmeter sufficient for your task for free.
But I wouldn't recommend any of their offerings if you have to pay for it.
Sears has had what looks like a decent multimeter on sale for $10
recently.

This link should be in everybody's toolbox.

www.pinouts.ru

One caution about testing unloaded power supplies...
depending on the quality of the design, a power supply with
no load on the 5V may have insufficient magnetic flux
to guarantee that all the voltages are in spec.
You can chase your tail forever trying to fix something that
ain't broke.

Are you absolutely sure you have compatible ram?
I've been in situations where ram that worked fine in
one board caused another board to act completely dead.

"Dustin" wrote in message
. 233.145...
"Adam" Wed,
17 Dec 2014 06:00:51 GMT in alt.comp.hardware.pc-homebuilt, wrote the
following message:

Host OS: Ubuntu Desktop 12.04 LTS
Motherboard: ASUS Sabertooth 990FX AM3+ AMD SATA 6Gb/s USB 3.0
ATX Computer Case: Antec Three Hundred ATX Mid Tower
Power Supply: OCZ ModXStream Pro 600W Modular


I am having trouble with power to brand new system.

After talking with OCZ tech support and doing a simple test,
we were able to get the PS fan to spin-up. OCZ Tech support
concludes that this is a strong indication that the PS is
functional.

Next, I suspect that the Antec case's I/O panel wiring to mobo pins
may be the culprit. The wiring seems fine to me but still no
power.

Take the wiring off the pins. Locate the power pins, touch them both at
the same time with a small screwdriver; See if your box powers up. if it
does, you've determined the problem is most likely in the panel wiring
and you can track it down from there.


No, shorting PWR-GND with a small screwdriver didn't work either.



--
My truck does not leak. It's just marking its territory!

On Wed, 17 Dec 2014 12:30:52 -0600, VanguardLH wrote:

mechanic, an inaccurate nym, wrote:

Adam wrote:

I am having trouble with power to brand new system.

So send it back to the shop!

He did. Adam *is* the shop. Look at the specs he gave. Did that look
like a pre-built or OEM build to you?

Didn't get that far - was it any good?