Is it safe to power on a motherboard outside of its case?

I have a new motherboard which needs a BIOS update to support a new CPU.

Thankfully I have an old (compatible) CPU handy. My plan is to install the old CPU, update the BIOS, then install the new CPU.

I'd prefer not to have to mount the motherboard in a case just to do the BIOS update bit.

Is it safe to power up the motherboard outside of its case? My understanding is that the case provides grounding for the motherboard – could the lack of grounding be an issue?

misha256

Posted 2014-06-19T05:56:05.280

Reputation: 10 292

5Some people even "glue" all their components to walls and let it run there :D – Ray – 2014-06-19T08:36:28.003

@PacMani: I've seen a shoebox install. Lots of glue! – dotancohen – 2014-06-19T08:48:36.337

someone even mounted it inside an old toilet :P – Ray – 2014-06-19T10:46:14.477

18Not only is it safe, assuming you follow the precautions listed in the answers below, it's in fact a good practice for new builds. Fully connecting all motherboard components outside the case and powering them on will quickly identify any components that might have been DOA. Once you've checked that the system boots, then you can install it into the case. – Lilienthal – 2014-06-19T11:47:58.340

My past 2 desktops have been bare motherboards sitting in a cardboard box. – Yuji Tomita – 2014-06-19T23:50:28.330

1As everyone else has said, no worries other than the usual. I've done it 100's of times. I/Others have cases made of plastic that don't provide grounding. Even then, metal cases are never grounded to anything. – user1596244 – 2014-06-20T11:51:14.967

4as @user1596244 said, metal cases are not grounded. The grounding of the Motherboard is provided by the PSU, which is of course grounded to the power grid. – iFreilicht – 2014-06-20T12:21:53.867

6Make sure to mount a cooling system even on your temporary CPU, otherwise it would become too hot very fast. – Gras Double – 2014-06-20T22:22:32.327

1@Lilienthal I wouldn't call this good practice. DOA parts are rare, if all works you are wasting a lot of time doing it twice for the exception. Also unmounted you are much more likely to cause damage through flexing the motherboard or shorting something out. – JamesRyan – 2014-06-23T11:26:31.733

Don't set the MB on the case, regardless what it is made of. Plastic cases may be coated with conductive paint. The purpose is to form a Faraday Shield to stop RF interference. The case might also be tied in to ground but usually is not as the shielding effect doesn't require it.

– DocSalvager – 2014-06-25T21:41:05.817

@user1596244: You will find that the metal case of a typical PC is most definitely connected to mobo ground and to PSU ground... assuming you've installed everything properly . Check it out with a DMM set on "ohms" if you don't believe this. – Jamie Hanrahan – 2014-08-06T04:46:04.107

I know and understand it. It just typically not the best ground in the system, I would much rather rely on the 24-pin ground than the one provided by 4 case screws holding the PSU in place. – user1596244 – 2014-08-06T11:17:27.037

Answers

Yes, it should be safe. Just be sure to put your motherboard on something not conductive, like cardboard box, and it should not touch anything that conducts electricity, including your main computer case. I did this few times. If you stop by in almost any computer shop, technicians do this sort of thing routinely.

mvp

Posted 2014-06-19T05:56:05.280

Reputation: 3 705

3Also, it is a bit harder to keep track of all wiring that runs around the MB when it is not in the case. So make sure none of the wires/cables get caught in the cooler fan. – Art Gertner – 2014-06-19T10:56:29.210

1Back in my day, they used to sell open racks (not enclosures) for mounting components, so everything was out in the open. This was handy for learning how PCs work, troubleshooting a suspect component, etc. Sometimes, these racks weren't even metal. – Patrick Seymour – 2014-06-19T12:50:23.087

1I learned quickly when I was starting out with assembling computers that they didn't need the case, and when building myself new pcs, I'd not order a case just to bring down the price, my room was a bunch of boards strewn around and connected all over the place for a decade. – stephenbayer – 2014-06-19T20:11:54.807

I built one for a LAN party once using spare parts from other party-goers. No case, but it didn't matter. I still won at most of the games. – phyrfox – 2014-06-20T03:15:49.897

4And don't drop any screws on it while it's running! – RomanSt – 2014-06-20T13:36:51.343

The case is only for convenience (well, and holding air filters), grounding is done through the power supply. – Jason C – 2014-06-20T13:45:08.003

11For the cardboard box, you can use the motherboard box itself -- it is sized perfectly. – Reid – 2014-06-20T16:34:27.927

@JasonC and some emf shielding... – cde – 2014-06-22T00:02:46.390

@stephenbayer: a case is useful for protecting those sensitive parts from the environment. A naked boards may much more easily get contact with liquid or conductive metals which is never good. So while it's not a problem to run a PC naked, given some basic precautions, a case is a good investment to protect those expensive parts. – Lie Ryan – 2014-06-23T08:36:12.477

@LieRyan agreed totally. I'm just saying all the parts work without a case. The answer to the question "Is it safe..." would be, probably not so much. – stephenbayer – 2014-06-23T15:54:25.877

Once, when I dismantled my old XBox (the first gen one), I re-housed it in a (clean) pizza box for a few weeks while I was tinkering with it. Still ran great! I did cut a chunk out of the top of the box and hot-glue a fan there though, to make sure it had adequate ventilation. – Doktor J – 2014-06-23T16:16:19.373

@JasonC It begs the question, why then are motherboard screw holes designed to be conductive and are connected to the ground?

– Jason – 2014-08-06T15:42:02.690

1@Jason That's an almost universal PCB design strategy; the intent is to provide multiple low-inductance ground connections for the case, so the case is grounded, which helps protect against RF interference as cde hinted at above. It's for the chassis, not for the motherboard. – Jason C – 2014-08-06T16:19:51.573

(Same idea as grounding the shield in shielded cable.) – Jason C – 2014-08-06T16:27:07.123

Yes, you can power on the motherboard outside of its case. Just keep some precautions, like laying a piece of cardboard underneath the board, and you're good to go.

Also, human body contains static charge, so ground the static by touching a grounded appliance or wiring a ground circuit. Static charge in the human body might damage sensitive electronic components of the motherboard.

Ricky

Posted 2014-06-19T05:56:05.280

Reputation: 311

I'm not sure how helpful "touching a grounded appliance" is for people wondering about this. "Touch a radiator" may be easier to explain ;) – Voo – 2014-06-19T09:44:55.890

Or the groundpin in your electrical socket (if present, in Europe it is) – Martijn – 2014-06-19T10:28:08.433

46Note that antistatic bags are specifically designed to be conductive. While they may be useful at preventing a static charge from building up and damaging an unpowered device, they also happen to be decent at shorting contacts of a powered device, thus potentially causing damage (though unlikely). Therefore, you really shouldn't be powering up any device while they are in or on an antistatic bag. – Bob – 2014-06-19T10:45:09.810

@Bob: I never knew that. I always considered it to be a safe thing to stick stuff on for this kind of thing. Point noted though! For anybody else interested in seeing more I just found http://electronics.stackexchange.com/questions/5990/do-antistatic-bags-have-conductive-interior-exterior-or-both that clarifies exactly how conductive, etc.

– Chris – 2014-06-19T11:13:32.540

4@Chris It's usually not overly dangerous, since the conductivity just has to be enough to prevent the buildup of a massive voltage for a static shock (therefore, unlikely enough to conduct the max of 12V for a motherboard). The problem is you can get cheap/crappy bags that are more conductive than they should be. Also, this means it's strictly worse than a plain insulator - so while a warning against it isn't really necessary, it's also not good to recommend for it. – Bob – 2014-06-19T14:43:02.073

At work we recently had a fire start in an antistatic tray. A lot of things had to go wrong at once, but if you treat something as safe under most conditions, you risk missing that last variable that changes it to unsafe. – Karl Bielefeldt – 2014-06-19T19:25:13.650

Not to mention the potential of electrocuting yourself... – BBlake – 2014-06-19T19:25:15.240

As a low level IT support technician, I consider the case to be my grounding appliance when working inside a machine. Therefore I would recommend touching something that's made of a similar material. Working on carpet and wearing polyester materials would tend to build up static more. Its not a huge consideration but I did have to blow one of my own motherboards this way before I took it seriously. Don't be like me, ground yourself just in case. – Dom – 2014-06-20T09:38:05.627

A good practice is to use an antistatic wrist strap.

– Roberto Gomez – 2014-06-28T04:29:09.533

The other answers you got are correct: it's definitely doable and something that is done all the time by professional/power/enthusiast users for all sorts of purposes.

What I would like to add is that, if you search online, you'll see that a lot of people will turn the motherboard ON using a screwdriver: they simply close the circuit between the 2 power pins using the metal part of the screwdriver. This is done because you no longer have a power button (since there is no case). The electrical current in there is extremely small, so there's zero chance of harm.

However, be very very careful if you use this technique. Touching the wrong pins can damage the motherboard. They usually have some protections in there for situations where people don't connect the cables properly, but you shouldn't rely on this.

To mitigate these risks, there are 3 possible solutions:

be super super careful when you do it
get the power button out of your case and connect it normally. It should work. It's a simple circuit-breaker
some motherboards (more expensive ones, dedicated to high-end PCs) have a power button on them. If yours does too, use that instead.

Radu Murzea

Posted 2014-06-19T05:56:05.280

Reputation: 327

Some motherboard vendors (notably Asus) provide internal power-on button – mvp – 2014-06-24T03:30:05.780

The case provides a number of benefits:

physical protection.
airflow management.

Generally, some electronic devices on PCBs operated outside the designed casing can end up running hotter.

This probably isn't an issue for short periods of use.

enter image description here
^{Example of desktop PC with fan in case (at top of photo)}

RedGrittyBrick

Posted 2014-06-19T05:56:05.280

Reputation: 70 632

Sounds strange. There should be much more air accessible around when no case is present, why would any devices become hotter? – Ruslan – 2014-06-20T10:49:48.743

4@Ruslan, in a case, there's a case-fan which actively pushes air across the motherboard. Although the CPU and PSU have their own fans, other components rely on a flow of air passing over the motherboard. This is an important part of the thermal design of many products. Without that active management of airflow you are reliant on convective movement of air only, this may be insufficient under some circumstances. – RedGrittyBrick – 2014-06-20T11:08:14.243

@RedGrittyBrick Never seen a case with its own fan. – kinokijuf – 2014-06-20T11:14:18.773

@kinokijuf first case I checked has two fans: photo.

– Ruslan – 2014-06-20T11:21:42.483

2@kinokijuf: I just opened up a desktop PC, took a photo and added it to my answer. They may be more common on servers but they can still be found in desktop PCs and notebooks too. Even if your PC relies in the PSU fan, that depends on the enclosure to ensure air is drawn across other components, without the enclosure, the airflow into the PSU comes from the room and not so much from across the motherboard. – RedGrittyBrick – 2014-06-20T11:25:05.613

@Ruslan …i meant that i have never seen it in the wild. At least where i live, most desktop PCs used are refurbished ones. – kinokijuf – 2014-06-20T11:27:14.233

This varies greatly depending on the board, the cpu, passive cooling, etc. But a fan in a mostly enclosed space has better suction than one in an open space. A wind tunnel in design, to push/pull circulate air over the parts. – cde – 2014-06-22T00:07:49.627

One thing to watch out for is add-in cards coming loose. On some cards, the rear connector bracket is long enough that it hangs below the bottom of the motherboard when the card is plugged in to the motherboard. This isn't a problem in a case when the motherboard is mounted on standoffs, but it can be a problem if you sit the motherboard directly on a hard flat surface - the weight of the motherboard can pull it away from the card, like so:

Diagram of potential issue

You may need to elevate the motherboard half an inch or so to prevent this.

nobody

Posted 2014-06-19T05:56:05.280

Reputation: 466

you waste your electrical shielding and get maybe some weird effect in nearby radios, or whatever transmitter - or in case you have strong senders nearby (maybe lay your nice smartphone on the motherboard) you induct some current somewhere on the motherboard, and if its an good one (means on the technological edge) there will be less room for errorcorrection of these ... also every wifi- bluetooth connection will be disturbed (at least a little) with this extra RF noise around. or in other words, you have to pay extra attention to the said shortcutting, dirt and dust probllem, maybe to water (in the air or simply your coke bruzzling around) AND the over the air electrical (non)shielding

jens viisuksena

Posted 2014-06-19T05:56:05.280

Reputation: 51

4Valid point about EMI here. However, you have to remember the fact that MBs are designed with enough shielding and MB manufacturers do not rely on computer outer casing as a main shielding for EMI noise. In fact, outer case is often made of plastic, so taking MB out, does not change the overall picture. – Art Gertner – 2014-06-19T13:09:19.243

Keep in mind that many of the locations for screws on a motherboard are ground points. The screw grounds to the case and the power supply to the walls ground.

I'm sure it will run without them grounded to the case but I'm also sure your board is safer well grounded.

Ever wonder why there is copper/gold around the screw locations on the motherboard?

steve

Posted 2014-06-19T05:56:05.280

Reputation: 612

1This is a good point and noted. Seems the consensus on the net is that the power cables and other connections (monitor, USB) will provide sufficient grounding. Searching the net I also found Asus sold (perhaps still does) motherboards in a box that doubles as a temporary case - that gives me some assurance that generally motherboards should be OK without screw sockets grounded. – misha256 – 2014-06-20T08:13:17.113

Inside a lab probably yes even if is a custom lab.

IF you make a safe place to work without any cable or power interrumption . you are talking about a BIOS upgrade, not a common software fail safe after format.

you can't say something is 100% safe for it, when was not been builded for it.

where will you place it?

on a carpet? you can burn it

on the floor? you can crash it

People may transit around and think is a shiny toy

Its case will provide many things

Hit protecion
Garbage protection
Anti-static protection
Pins will not touch any thing but the air
Grounding .

And yes. you can't mount it outside it case. not a good practice.. more like a gamer practice.

Quijote Shin

Posted 2014-06-19T05:56:05.280

Reputation: 195

Strictly no, in practice definitely yes: yes you can power up the motherboard outside of its case, or just forget the case altogether and harvest the power supply. You can happily run such a system with all of your components on the desk/shelf/whatever, great way to have an "extra" PC around in plain site that doesn't look like your typical PC.

But to explain the strictly no, having exposed components around makes it easier to short some circuits, or just get dirty faster, or collect spilled coffee etc... You probably don't want to drill some holes in metal over the motherboard, little metal filings going everywhere won't be good for that. Once you get used to having the mobo in the open, you tend to not notice these little mistakes until its too late.

The power supply connection(s) provide the ground to the mobo, not the case. The case just happens to physically touch the power supply's case, which is grounded, and thus the case gets ground as well.

Chris O

Posted 2014-06-19T05:56:05.280

Reputation: 279

If the motherboard is screwed into the case, it does connect its ground to the case — even if you keep PSU outside the case. That's what the soldered lands around the motherboard holes do. – Ruslan – 2014-06-20T11:33:47.147

@Ruslan Yes the motherboard has a grounding connection around each of the screw holes, you're right about the circular solder leads. However those are "optional" grounding connections, the "main source" of ground must come from the PSU itself, some of the cables provide this. Grounding the main case and the PSU case is an extra safety feature. Having the motherboard out in the open loses that extra safety feature. – Chris O – 2014-06-20T12:29:30.423

It seems like there are kinda two meanings for "ground". In an electronic circuit, your normal "ground" pin is often a local ground...just a voltage sink, electron pool, or what have you...and basically everything uses it. The case, on the other hand, provides a "chassis ground", an honest-to-goodness ground that connects to the third blade/pin on your power cord (though it probably does this indirectly through the power supply's own chassis ground). – cHao – 2014-06-21T22:31:53.860

Something that has not been answered in previous answers:

The power supply will provide grounding for your motherboard. This means that, if you plug your power supply in a grounded wall socket, then automatically the components attached to the power supply are more or less grounded.

However, your computer case is not automatically grounded; the screws on your motherboard may not necessarily be connected to your motherboard's ground. Most commonly, the computer case is grounded by simply screwing in the power supply, since the case of your power supply is grounded.

So, yes, it is 'safe' to run your motherboard outside of a computer case (if you do not own a cat), but it is not 'safe' (from a grounding perspective) to run your power supply outside of the computer case.

Sanchises

Posted 2014-06-19T05:56:05.280

Reputation: 163

In the above image there are 3 different types of "grounds" (3 different symbols) and they are not connected to each other:

ground of the case (power supply) connected to the "ground" wire on the wall outlet
ground on high-voltage DC side (looks like triangle)
ground on low voltage DC side (look next to each DC output - capacitor is connected there)

So, motherboard is NOT "grounded" by power supply: it is NOT connected to the "Ground" wire (NOT connected to the "ground" on the wall outlet). It is connected to it's own "low-DC-side" ground which is isolated from the outside world.

vlad

Posted 2014-06-19T05:56:05.280

Reputation: 1

1Interesting research! But are you sure about this? The power supply itself is encased in metal and this casing is grounded to earth. Installing the power supply into a metal PC case will extend grounding to the case too. Then, installing the motherboard onto the brass stand-offs inside the PC case will extend grounding to the motherboard too. Am I mistaken? :-) M – misha256 – 2014-06-23T03:22:12.943

1One more thought: if a motherboard's ground was isolated from the outside world, wouldn't that cause all sorts of issues when we connect external peripherals to the motherboard like Monitors, TVs, powered USB devices... I'm thinking nasty ground-loops and like? – misha256 – 2014-06-23T03:50:13.277

Yes, but less.

(Prevent shorts, prevent electromagnetic discharge, prevent strong magnetic fields, try not to get it dirty, that's all)

Lodewijk

Posted 2014-06-19T05:56:05.280

Reputation: 131

As long you don't do it on a metal surface or put some material at the bottom which can cause short circuit its not a problem.I remember setting up my computer when I was 9 years old all of the computer parts were out of the case.They were all over the bed.Use bed if you are doing it on your bedroom.Its soft and there is no way for it pass the electricity but be aware it can get really dirty :D

Also remember in order to start the computer you need to short circuit the pins on the motherboard by yourself cause probably the switch cable of the case will come to short to attach on it.Be careful while doing that a wrong short-circuit can cause you trouble.

But of course its still best to put in into case.Dont use your pc like that just test whatever you want and put it back in.

Bugra Sezer

Posted 2014-06-19T05:56:05.280

Reputation: 1

Yes the gold/copper screw rings on your mobo is ground but its all interconnected through the motherboard these ground screws are only built in to prevent mobo fires in a specific component. Sometimes grounding fails along the way through the mobo these ground screws are a failsafe but the mobo gets ground from the psu mobo plug. Ground screws are not needed unless you are overclocking (produces alot of heat) which can make the mobo's grounding path fail.this is the only reason these screws are in place a just in case something goes wrong

mizzter mocha

Posted 2014-06-19T05:56:05.280

Reputation: 1