Anyone skilled in computer boot up process?

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My system, without a case, does not have any screw to hold the expansion cards in place, so naturally the cards suffer from bad connection.

But the graphics card has a strange behavior. I need to slightly hold the graphics card upright when I cold/warm boot the system, after I see the POST screen I can let go the gfx card and it will work properly, for hours of non-stop gaming. But if I do a reset, it will still fail to boot.

What explanation is there for this behavior?

PRSNT pins are measured to be shorted with the card in both positions.

The card leans away from the CPU when not supported by the piece of plastic which I am using to fix the problem.

(I'm not interested in the solutions, because I already have a solution; I want to find out why the system behaves that way.)

Which PCI-E pins are needed only during bootup?
 
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dude, expansion cards NEED THOSE SCREWS TO WORK!

You can't just support a card entirely on the pci-x x16 socket! get some screws for the case and that will fix your problem, it needs all of those pins, it can't just run on a whole half of a socket.

imagine if someone got a scalpel and cut away half of the nerves that connect your spinal cord to your brain :) nobody would work that well like that either, the pci-e x16 socket is like a spinal cord to the graphics card.

the reason why its doing it is because the pci socket has 2 rows of pins and when the gfx card is pulling down on the PCB board of the gfx card it only allows contact to one side of these pins which are located inside of the pci socket, most likely the bottom row of pins aren't getting sufficient contact inorder for it to work properly.

when you have the screws mounting the graphcs card higher up to the chassis, it makes a perfect contact surface with BOTH rows of pins that are located inside of the pci socket, in essence taking the huge strain off of the pci socket.

failure to do this in a situation like for example where your computer is falling off of the table WILL result in the graphics card ripping the entire pci-e socket off of the motherboard once it lands on the floor, as the entire weight of the graphics card is exerted upon the pci-e slot on the motherboard, rendering it useless without replacing the motherboard.
 
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No case means you are in SEVERE violation of any countries EMI radiation laws. I suspect you just have a card seating issue. The connectors are not designed to hold the card up. Get a case.

Which pins are used on boot will depend completely on the card and driver. THere is no blanket easy answer.

freax,
Bold statement. You may be surprised in the backgrounds of DIY audio members. :)
 
As mentioned, its probably poor grounding (case) or poor connection to the PCI-e slot due to no support.

As far as EMI, I really think that's a red herring. Every individual component must adhere to EMI laws, whether or not it has a case:

(not my pic, but I own the same case for my home rig)
An externally hosted image should be here but it was not working when we last tested it.

Lian Li PC-Q06
 
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<snip>

As far as EMI, I really think that's a red herring. Every individual component must adhere to EMI laws, whether or not it has a case:

No it's not, the cards are designed to meet the specified EMC standards when installed inside a case that also meets those standards. (All of the cases I've purchased in recent years indicate that they meet FCC Class B EMC standards which is what is required here in the U.S. for home use.)
 
But as far as I know there is no law that prevents an end user from using his PC without a case. Those regulations are for manufacturers. In the same way that I could build and install a wireless home intercom that scrambles my own TV reception. A different story if it also scrambles all my neighbors' TV reception.
The OP's sagging card must have a non- or high resistance connection that fails the POST. Or more than one.
 
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But as far as I know there is no law that prevents an end user from using his PC without a case. <snip>
The OP's sagging card must have a non- or high resistance connection that fails the POST. Or more than one.

FWIW, I think you are probably right, and practically speaking if you interfere with no one but yourself.... :p There would have to be complaints of interference over some extended period - I imagine in today's fiscal environment that the FCCs field engineering force is pretty constrained.

A whole lot of issues with running the PC outside of a case besides EMC including susceptibility to destruction by ESD, pets, conductive foreign objects falling into unfortunate spots, dust and dirt, and the like.. Bottom of the barrel and used cases are dirt cheap on eBay and can often be picked up off the street on trash day.. :D
 
Considering that I am going to go for my ham licence someday I must do my best to keep the airwaves clean today.

Frankly I think unregulated unshielded cases should be sold to those who hold a ham licence, that will boost licence numbers by a great degree and keep the noisy computers shielded.

Who knows, some motherboard manufacturer might someday release a motherboard that puts out 1 watt of RFI and matches it perfectly into the airwaves.
 
No case means you are in SEVERE violation of any countries EMI radiation laws. I suspect you just have a card seating issue. The connectors are not designed to hold the card up. Get a case.

Seconded.

freax,
Bold statement. You may be surprised in the backgrounds of DIY audio members. :)

Yes and considering that this is diyaudio.com and not a computer related forum, They are typically too busy to give advice on threads where a simple lack of experience with computers is the OP's issue at hand, given a few more years and I'm sure that a few thousand dollars worth of equipment gets blown up and he will learn his lessons, Like I did.

And personally I would much prefer to have those people that you mention working on other more technical audio related threads than to have to answer a question like this, and if it bolsters peoples perception of diyaudio.com as a place where computer users with issues come to get advice then those engineers wont ever get anything done, they will be answering questions like this all of the time.

This thread was answered and I question its validity as a worthwhile thread in the first place, if I had made a thread like this then it would have never gotten answered, I was kind in giving the best possible answer that I could give the OP, and thats with 15 years worth of computer experience under my belt.

I've been repairing computers since 1996 and considering that the OP has taken such harsh treatment to his equipment ticks me off, it doesn't make me angry but it does make me question why computers these days dont have legal requirements as to their safety.

If I hadn't been so harsh the OP could have damaged his motherboard and his power supply and his graphics card through short circuits, ontop of that pissed off a ham radio operator by not using a case, and now that I think about it ontop of that held his life in jeapoardy.


A hypothetical for you guys to think about:
Anyone who knows what they are talking about should be able to tell the OP that running without a case puts him and anyone else he knows in great danger if the power supply should ever fail and decide to put mains voltages onto the DC bus.

If the OP had no case what is going to stop him or someone else from grabbing a part of the computer and getting killed, a computer case is earthed and this is one of the reasons why motherboard mount points are today earthed to the chassis, aswell as the expansion slot header, whereas back in the 80s and 90s the motherboard was floating, today though its beneficial for both an emissions standpoint and a safety standpoint to have them earthed.

Granted its not such an issue as it used to be but it is still a possibility, and back in the 90's it WAS a serious issue because we had the mains switch coming to the front of the case through the case.

And considering that there is a tendency to have the cheapest possible power supply in computers these days I don't see why we shouldn't put a blanket safety precaution on this entire topic and consider uncased computers as inherently dangerous.

Another theoretical scenario:
The OP is using his unshielded unearthed computer during a lightning storm, he has his adsl modem plugged into the phone line and his computer is plugged directly into the modem via ethernet, he is holding the keyboard on his lap and the mouse in his right or left hand.

What happens? The lightning HOPEFULLY goes through his motherboard, up the ATX cable, into the power supply and is earthed out safely.

What happens if the lightning doesn't follow that path? the OP is shocked, possibly killed, through his keyboard and mouse.

What would happen if the motherboard was inside of a computer case? Hopefully the lightning will travel directly from the ethernet connector straight to the chassis and safely into the power supply earth cord, maybe not even damaging anything but the ethernet port.
 
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The idea that you can safely run a computer without a computer case simply because all of the nasty mains voltages are inside of a metal box is a myth, and I question the intelligence of anyone who thinks otherwise simply because there havent been any reports of people being killed yet, but we have tons of people in the overclocking community who think its a great idea to popularize this and not only take a **** all over the radio waves by not having a case but also put themselves in danger.

Especially with perspex computers, the open metal frame ones should be safe, earthed, but who knows if a hinge is properly conducting or not, there are some pretty wild open cases out there.
 
The idea that you can safely run a computer without a computer case simply because all of the nasty mains voltages are inside of a metal box is a myth, and I question the intelligence of anyone who thinks otherwise simply because there havent been any reports of people being killed yet, but we have tons of people in the overclocking community who think its a great idea to popularize this and not only take a **** all over the radio waves by not having a case but also put themselves in danger.

Especially with perspex computers, the open metal frame ones should be safe, earthed, but who knows if a hinge is properly conducting or not, there are some pretty wild open cases out there.

...

There are some comercially available open cases to be found, handy for overclockers and whatnot. The highest voltage out from the psu is 12v, afaik there is no law or regulation stating 12v as hazardous or illegal to work with in any case, 12v is legal to work with for anyone, it is possible to screw up though, know someone who managed to shorten a big lead battery with a wrench, he was'nt looking, the wrench melted. The psu itself is in a box, properly earthed and everything.

I think maybe there is a problem with the -5V connection on the PCI slot, not sure in this particular case since there is little info, but the system does use -5v to sense loads. If you connect the -5v and ground on a computer psu to a load (like a fan or resistor) you can swith the psu on without any computer parts attached. Handy for testing car stereo at home.
 
But as far as I know there is no law that prevents an end user from using his PC without a case.

Yes there is. At least in the USA. I can't speak for your country. This is why we have the ratings and products need to be tested. The manufactures have to certify their products. If you modify that configuration, you are in violation. It is disrespectful , stupid and illegal. The law here says no one may interfere with others communications.

We have these laws so people like you won't mess up others communications. FM, as is used by ambulance, fire, and police is very susceptible. Many medical devices are not as immune as they should be.
 
As with many claims, as soon as some evidence is provided "people like me" will consider a changing of mind.
Of course there are laws against radiated interference. A PC interfering with ambulance/police/fire comm is absurd.
PS Texas is the 28th state of the USA.
 
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