Running a PC outside of a computer case

[D]

I've built one computer, and will soon be building another. I would
like to initially set up & test this new machine on the bench, outside
of a computer case (simply connecting the PSU, etc., w/o all the bits
being in a case). Seems straightforward, but I have a couple questions.
First, am I correct that the front panel on/off switch generally used
to start the PC is simply a momentary contact switch that briefly
connects the "PW+" and "PW-" terminals on the MOBO? Same with the
reset/reboot switch function, using "res+" and "RES-"? Also, is it
necessary to run a ground wire between the PSU case, and one of the MOBO
pads where the screws go to attach the MOBO to the case when installed?
Since the metal case would "ground" these 2 together, I was wondering.
If this is required, should all metal cases (HDD, DVD drive, etc) be
so "grounded together"?

Any other helpful points about running a PC on the bench this way would
be greatly appreciated.

TIA

Dan

 

[Meat Plow]

I've built one computer, and will soon be building another. I would
like to initially set up & test this new machine on the bench, outside
of a computer case (simply connecting the PSU, etc., w/o all the bits
being in a case). Seems straightforward, but I have a couple questions.
First, am I correct that the front panel on/off switch generally used
to start the PC is simply a momentary contact switch that briefly
connects the "PW+" and "PW-" terminals on the MOBO? Same with the
reset/reboot switch function, using "res+" and "RES-"? Also, is it
necessary to run a ground wire between the PSU case, and one of the MOBO
pads where the screws go to attach the MOBO to the case when installed?
Since the metal case would "ground" these 2 together, I was wondering.
If this is required, should all metal cases (HDD, DVD drive, etc) be
so "grounded together"?

Any other helpful points about running a PC on the bench this way would
be greatly appreciated.

TIA

Dan

It will run just fine without a case except that most cases add
additional airflow to cool the CPU and other components.

 

[William Sommerwerck]

"Obviously" (???) you're trying to avoid mounting the MOBO. But I suspect
that the additional work needed to place the MOBO on a clean, non-conductive
surface, and hold it there safely -- along with all the other components --
will be greater than the work needed to mount it safely in the case.

You might want to reconsider.

 

[D]

Hell, most work table tops, or a piece of cardboard, would do the trick.

The company I used to work for did this all the time when they built
systems; lay everything out on the bench with a monitor and keyboard and
power it up. Simple, so long as you use common sense and watch what
you're doing.

Thanks for the replies. I only have one ATX case, which currently
contains my working computer, which I want to have available until I get
the new bits checked out, OS loaded, up and running, etc. I have a
momentary contact switch from an older machine which should do nicely
for powering up, although I've heard of people simply using a small
screwdriver for this. I'd rather not run the risk of accidentally
shorting to the wrong terminals, though. Agreed care is in order,
probably don't want to have my pitcher of Koolaid on the same table as
the spread-out bits, but I think it should be OK.

I gather then that there's no need to ground the PSU case & other bits
together with clip leads?

Dan

 

[William Sommerwerck]

I gather then that there's no need to ground the PSU case

& other bits together with clip leads?

Probably not, as the cables have the necessary ground wires.

 

[David Nebenzahl]

"Obviously" (???) you're trying to avoid mounting the MOBO. But I suspect
that the additional work needed to place the MOBO on a clean, non-conductive
surface, and hold it there safely -- along with all the other components --
will be greater than the work needed to mount it safely in the case.

Hell, most work table tops, or a piece of cardboard, would do the trick.

The company I used to work for did this all the time when they built
systems; lay everything out on the bench with a monitor and keyboard and
power it up. Simple, so long as you use common sense and watch what
you're doing.

 

[David Nebenzahl]

Thanks for the replies. I only have one ATX case, which currently
contains my working computer, which I want to have available until I get
the new bits checked out, OS loaded, up and running, etc. I have a
momentary contact switch from an older machine which should do nicely
for powering up, although I've heard of people simply using a small
screwdriver for this. I'd rather not run the risk of accidentally
shorting to the wrong terminals, though. Agreed care is in order,
probably don't want to have my pitcher of Koolaid on the same table as
the spread-out bits, but I think it should be OK.

I gather then that there's no need to ground the PSU case & other bits
together with clip leads?

No, the case isn't required as a ground. All needed grounds are already
in the connection betwixt PSU and motherboard.

Of course, you won't have an FCC-compliant setup without the case, RF
emission-wise, but no need to sweat that so long as you don't plan on
running the "naked" setup more than a short time.


--
The current state of literacy in our advanced civilization:

yo
wassup
nuttin
wan2 hang
ok
where
here
ok
l8tr
by

- from Usenet (what's *that*?)

 

[D]

No, the case isn't required as a ground. All needed grounds are already
in the connection betwixt PSU and motherboard.

Of course, you won't have an FCC-compliant setup without the case, RF
emission-wise, but no need to sweat that so long as you don't plan on
running the "naked" setup more than a short time.

Hadn't considered the RF emissions. If that pitcher of Koolaid I
mentioned starts to boil (or my garage door keeps going up and down),
I'll now something's up! ;-)

Thanks again everyone for the helpful replies.

Dan

 

[Grant]

I've built one computer, and will soon be building another. I would
like to initially set up & test this new machine on the bench, outside
of a computer case (simply connecting the PSU, etc., w/o all the bits
being in a case). Seems straightforward, but I have a couple questions.
First, am I correct that the front panel on/off switch generally used
to start the PC is simply a momentary contact switch that briefly
connects the "PW+" and "PW-" terminals on the MOBO? Same with the
reset/reboot switch function, using "res+" and "RES-"? Also, is it
necessary to run a ground wire between the PSU case, and one of the MOBO
pads where the screws go to attach the MOBO to the case when installed?
Since the metal case would "ground" these 2 together, I was wondering.
If this is required, should all metal cases (HDD, DVD drive, etc) be
so "grounded together"?

Any other helpful points about running a PC on the bench this way would
be greatly appreciated.

I do temporary lashups like that to test gear, need to put the mobo on a
book or something non-conducting to raise the edge where NIC and display
cards go. Don't need extra grounds. The power is momentary contact, low
voltage, shorting out the connectors in that area shouldn't do a damage as
they're either switch inputs or current limited LED outputs.

Put the hard drive where you wont bump it, probably on top of the optical
drive. When in doubt, sticky tape stuff down. You want LEDs in the power
and HD positions to get an idea what's happening. Speaker too, for the
beeps. Pair of momentary switches or wires for power and reset... I keep
an old switch + LED harness from a discarded case around for controlling a
bare mobo.

Grant.

 

[D]

I've built a few dozen PCs over the years. I would never bother
running the system out of the case. Mine nearly always work fine ( one
exception ) and then you'll have to unplug and mount it anyway and
plug together again. You're more likely to screw it up OUT of the case
so why take the chance and waste the time? BTW the case / power supply
I'm using now - the wife's machine - is on its 4th motherboard. The
latest change 2 weeks back took an hour - so short because the old and
new boards are nearly identical and didn't require any re-installation
of the software. The newer board can use the higher power/speed Phenom
II processor now in it.

G²

I rely quite heavily on my PC on a daily basis, and don't really want to
be without a functional machine. In order to load the OS & see if
everything is operable, I only need to connect 1 HDD, 1 DVD drive, the
vid card & monitor, keyboard, mouse & PSU. The only bit I'll need from
the existing machine is the vid card, an easy R&R in either direction.
No big deal, and if there is a problem, a DOA component, perhaps, it's a
lot less trouble finding out this way and dealing with getting a
replacement than removing the new board & completely reassembling my
working unit so I have it in the meantime.

 

[D]

I do temporary lashups like that to test gear, need to put the mobo on a
book or something non-conducting to raise the edge where NIC and display
cards go. Don't need extra grounds. The power is momentary contact, low
voltage, shorting out the connectors in that area shouldn't do a damage as
they're either switch inputs or current limited LED outputs.

Put the hard drive where you wont bump it, probably on top of the optical
drive. When in doubt, sticky tape stuff down. You want LEDs in the power
and HD positions to get an idea what's happening. Speaker too, for the
beeps. Pair of momentary switches or wires for power and reset... I keep
an old switch + LED harness from a discarded case around for controlling a
bare mobo.

Grant.

Thanks Grant, good tips ;-)

Dan

 

[Baron]

D Inscribed thus:

I notice that no one in this whole thread has mentioned taking suitable
precautions against causing damage from static discharge !

 

[Meat Plow]

D Inscribed thus:

I notice that no one in this whole thread has mentioned taking suitable
precautions against causing damage from static discharge !

And in your opinion, this indicates what?

 

[William Sommerwerck]

I notice that no one in this whole thread has mentioned

taking suitable precautions against causing damage
from static discharge!

It's implicit. It's assumed anyone who wants to do this knows the routine.

 

[Meat Plow]

It's implicit. It's assumed anyone who wants to do this knows the
routine.

That's what I thought also. You need to be aware of ESD precautions
before you experiment with most modern electronics. I've been using an
anti-static mat and wristband for a good 25 years. I've run my fair share
of computer equipment while testing components using a motherboard set
atop a non-conductive surface.

 

[Baron]

Meat Plow Inscribed thus:

And in your opinion, this indicates what?

Ignorance ! An awful lot of the new build failures that I see are from
people who have no understanding of how easy it is to cause damage to
components simply from not being aware that damage can occur during
handling.

It seems that all made the assumption that the OP is aware of this. The
original question suggests that the OP isn't !

 

[Baron]

Meat Plow Inscribed thus:

I would suspect that based on the OP question, that might not be a safe
assumption.

That's what I thought also. You need to be aware of ESD precautions
before you experiment with most modern electronics. I've been using an
anti-static mat and wristband for a good 25 years. I've run my fair
share of computer equipment while testing components using a
motherboard set atop a non-conductive surface.

I don't disagree. But then you and I have been doing this kind of work
for a good many years. I'll bet that you will have had odd failures,
particularly in the early years that you couldn't explain. ;-)

 

[D]

Meat Plow Inscribed thus:


I would suspect that based on the OP question, that might not be a safe
assumption.


I don't disagree. But then you and I have been doing this kind of work
for a good many years. I'll bet that you will have had odd failures,
particularly in the early years that you couldn't explain. ;-)

I am assuming grounding myself on the grounded PSU case would be
sufficient, correct?

Dan

 

[William Sommerwerck]

I am assuming grounding myself on the grounded PSU

case would be sufficient, correct?

It depends on what you mean by "grounding yourself". Touching the case once
might not be enough, as moving around can generate an electrostatic charge.
The safest thing is to wear a grounded conductive wristband.

 

[Meat Plow]

Meat Plow Inscribed thus:

Ignorance ! An awful lot of the new build failures that I see are from
people who have no understanding of how easy it is to cause damage to
components simply from not being aware that damage can occur during
handling.

So that means since you were the only one to pick up on this that
everyone else in SER is ignorant.

Thanks for expressing your true feelings.