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Monitor not recognising it's connected, possible CPU issue.

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November 17, 2011 9:53:31 AM

Well it's a little more complex than that. To begin with the computer would just lose power randomly, then it would cut out a few seconds after it was turned on. I assumed it was an issue to do with the PSU but asked a friend who knows more about this sort of thing than myself to have a look. He said it was probably a mobo issue because there were no beeps when booting. So I got a new mobo, cheap as I could as the rig is a couple of years old and new ram for it.

Now the rig starts up, fans run etc. Still monitor goes in to power saving mode. Tried taking out my gfx card and plugging it into the mobo, still nothing. So my mate now thinks it's the CPU. I don't want to fork out more cash only for it to be something else again. So if anyone has a clue, i'd love to know.

Thanks.
November 17, 2011 10:04:48 AM

bezzah said:
Well it's a little more complex than that. To begin with the computer would just lose power randomly, then it would cut out a few seconds after it was turned on. I assumed it was an issue to do with the PSU but asked a friend who knows more about this sort of thing than myself to have a look. He said it was probably a mobo issue because there were no beeps when booting. So I got a new mobo, cheap as I could as the rig is a couple of years old and new ram for it.

Now the rig starts up, fans run etc. Still monitor goes in to power saving mode. Tried taking out my gfx card and plugging it into the mobo, still nothing. So my mate now thinks it's the CPU. I don't want to fork out more cash only for it to be something else again. So if anyone has a clue, i'd love to know.

Thanks.



Well consider this, its your graphics card!!
November 17, 2011 10:06:19 AM

Sounds like the graphics card to me, does the new board have onboard graphics? if so does it work ok when using that instead?

You could try the graphics card in another pc to test it, if you have access to one.
Related resources
November 17, 2011 10:19:24 AM

Well I've just tried an old graphics card and still nothing, though there is every chance that thing is knackered after being in a box, in a cupboard for years. I don't have another machine, I'll see if a friend can help me out. "Integrated Intel Graphics Media Accelerator (Intel® GMA X4500)
" guessing that counts as onboard?
November 17, 2011 11:09:14 AM

"Integrated Intel Graphics Media Accelerator (Intel® GMA X4500)" is onboard graphics, remove your graphics card and plug into the onboard graphics.

If you still get nothing, it could be a faulty vga cable or monitor.
November 17, 2011 11:24:17 AM

right well tried intergrated and nothing, it isn't the vga or the monitor which i checked by plugging into my laptop.
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a b C Monitor
November 17, 2011 11:26:14 AM

Or power supply.

No signal on monitor? If you get a single short beep, possibly bad monitor, cable, or video card.

No single short beep? Your system is not booting, so anything inside the box could be the problem.

(Assumes you have system speaker installed. And if your system don't work, you need one badly.)

Instead of just guessing or following random suggestions, try some systematic troubleshooting. You may still need some guesswork, but you will need a lot less.

When you are asking for help, always start off with the system specifications. Then, is it a new build that has never worked or is a previously working computer that now doesn't. Is it an upgrade that you are having problems with?

The Great Carnack is dead. We need you to tell us these things. Each of the three problems about require somewhat different troubleshooting techniques.

Work systematically through our standard checklist and troubleshooting thread:
http://www.tomshardware.com/forum/261145-31-read-postin...
I mean work through, not just read over it. We spent a lot of time on this. It should find most of the problems.

If not, continue.
The following is an expansion of my troubleshooting tips in the breadboarding link in the "Cannot boot" thread.

I have tested the following beep patterns on Gigabyte, eVGA, and ECS motherboards. Other BIOS' may be different, but they all use a single short beep for a successful POST.

Breadboard - that will help isolate any kind of case problem you might have.
http://www.tomshardware.com/forum/262730-31-breadboardi...

Breadboard with just motherboard, CPU & HSF, case speaker, and PSU.

Make sure you plug the CPU power cable in. The system will not boot without it.

I always breadboard a new build. It takes only a few minutes, and you know you are putting good parts in the case once you are finished.

You can turn on the PC by momentarily shorting the two pins that the case power switch goes to. You should hear a series of long, single beeps indicating memory problems. Silence indicates a problem with (in most likely order) the PSU, motherboard, or CPU. Remember, at this time, you do not have a graphics card installed so the load on your PSU will be reduced.

If no beeps:
Running fans and drives and motherboard LED's do not necessarily indicate a good PSU. In the absence of a single short beep, they also do not indicate that the system is booting.

At this point, you can sort of check the PSU. Try to borrow a known good PSU of around 550 - 600 watts. That will power just about any system with a single GPU. If you cannot do that, use a DMM to measure the voltages. Measure between the colored wires and either chassis ground or the black wires. Yellow wires should be 12 volts. Red wires: +5 volts, orange wires: +3.3 volts, blue wire : -12 volts, violet wire: 5 volts always on. Tolerances are +/- 5% except for the -12 volts which is +/- 10%.

The gray wire is really important. It should go from 0 to +5 volts when you turn the PSU on with the case switch. CPU needs this signal to boot.

You can turn on the PSU by completely disconnecting the PSU and using a paperclip or jumper wire to short the green wire to one of the neighboring black wires.
http://www.youtube.com/watch?v=5FWXgQSokF4&feature=yout...

A way that might be easier is to use the main power plug. Working from the back of the plug where the wires come out, use a bare paperclip to short between the green wire and one of the neighboring black wires. That will do the same thing with an installed PSU. It is also an easy way to bypass a questionable case power switch.

This checks the PSU under no load conditions, so it is not completely reliable. But if it can not pass this, it is dead. Then repeat the checks with the PSU plugged into the computer to put a load on the PSU.

If the system beeps:
If it looks like the PSU is good, install a memory stick. Boot. Beep pattern should change to one long and several short beeps indicating a missing graphics card.

Silence, long single beeps, or series of short beeps indicate a problem with the memory. If you get short beeps verify that the memory is in the appropriate motherboard slots.

Insert the video card and connect any necessary PCIe power connectors. Boot. At this point, the system should POST successfully (a single short beep). Notice that you do not need keyboard, mouse, monitor, or drives to successfully POST.
At this point, if the system doesn't work, it's either the video card or an inadequate PSU. Or rarely - the motherboard's PCIe interface.

Now start connecting the rest of the devices starting with the monitor, then keyboard and mouse, then the rest of the devices, testing after each step. It's possible that you can pass the POST with a defective video card. The POST routines can only check the video interface. It cannot check the internal parts of the video card.
November 17, 2011 11:51:57 AM

Processor:Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (4 CPUs) (old)
Memory:Kingston 4GB DDR3 1333MHz HyperX Blu Memory Module CL9 1.5V (new)
Motherboard:MSI G41M-P28 G41 Socket 775 8 Channel Audio mATX Motherboard (new)
Hard Drive:200 GB (old)
Video Card: PowerColor ATI Radeon HD 4870 (1GB)
(old)

I don't have a speaker, so the beeps are of no use to me at the moment. damn.
November 17, 2011 12:06:00 PM

bezzah said:
right well tried intergrated and nothing, it isn't the vga or the monitor which i checked by plugging into my laptop.


The only other think I can think of is resetting your bios to default, it is possible that it is set to use the pcie card and will not use the onboard graphics until it is changed.

You won't be able to change it in the menu because you have no working display, the only other way is to remove the cmos battery.

Not sure what else to suggest really. If you don't want to spend money replacing parts you may not need its probably best to take it to a computer shop. They will be able to tell you in minutes whether it is the power supply or graphics card.

They may even test it for free if you buy the parts you need from them.
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a b C Monitor
November 17, 2011 12:42:20 PM

bezzah said:
Processor:Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz (4 CPUs) (old)
Memory:Kingston 4GB DDR3 1333MHz HyperX Blu Memory Module CL9 1.5V (new)
Motherboard:MSI G41M-P28 G41 Socket 775 8 Channel Audio mATX Motherboard (new)
Hard Drive:200 GB (old)
Video Card: PowerColor ATI Radeon HD 4870 (1GB)
(old)

I don't have a speaker, so the beeps are of no use to me at the moment. damn.


and what power supply?
November 17, 2011 12:46:54 PM

Well I just tried resetting the cmos, no joy. I'm just going to have to take it into a shop tomorrow, like I should have done in the first place. Thanks everyone for their help, much appreciated!
November 17, 2011 12:58:12 PM

13thmonkey said:
and what power supply?


Had to search for the order email, "Manufacturer : OCZTECH Product : 600W Active PFC GameXStream"
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November 17, 2011 2:24:45 PM

I have had this same thing happen. Believe me, I bet its your power supply.
PSU's have more than 1 rail, 1 rail can go bad, like the one supplying power to the board and/or CPU, or video card, while the rail supplying power to things like your fans and lights and drives can still be functioning, leading you to believe the PSU is fine when it's actually toast.
November 17, 2011 2:28:53 PM

jitpublisher said:
I have had this same thing happen. Believe me, I bet its your power supply.
PSU's have more than 1 rail, 1 rail can go bad, like the one supplying power to the board and/or CPU, or video card, while the rail supplying power to things like your fans and lights and drives can still be functioning, leading you to believe the PSU is fine when it's actually toast.


That's what I thought along, thanks man. See if I can get a reasonably priced PSU.
November 17, 2011 2:52:51 PM

jitpublisher said:
I have had this same thing happen. Believe me, I bet its your power supply.
PSU's have more than 1 rail, 1 rail can go bad, like the one supplying power to the board and/or CPU, or video card, while the rail supplying power to things like your fans and lights and drives can still be functioning, leading you to believe the PSU is fine when it's actually toast.


With yours were the fans on your graphics card and CPU heat sinc running?
a b à CPUs
November 17, 2011 2:54:18 PM

Yes, CPU fan, case fans, drives, everything was running, just nothing would happen.
November 17, 2011 3:02:02 PM

jitpublisher said:
Yes, CPU fan, case fans, drives, everything was running, just nothing would happen.

Exactly the same as mine, you sir, are a life saver!
November 17, 2011 5:42:38 PM

one quick question, before I changed the motherboard and the ram the machine wouldn't even turn on. It would cut out 2 seconds after it began to power up. If it is the power supply and it certainly sounds like it is from whats been said, then why does it not turn on fully. This is my old motherboard http://www.tigerdirect.com/applications/SearchTools/ite...

It crossed my mind that as it was a better motherboard than the replacement then it required more power to run. Othercourse that's my probably my lack of knowledge.
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November 17, 2011 6:14:28 PM

I had a cheapy POS PSU (700w on the package but probably gave like 300w in reality) from years ago when I didn't know any better.

Well, it started having problems one day. I turned the computer off to give it a rest for a few days and it wouldn't come back on when I came back to it. More precisely, it would come back on, but only if I hit the power button again every time it lost power (which it always did within 1 to 5 seconds). After enough times (like 30) it would come on and stay on like nothing ever happened.

I started disconnecting things like hard drives, CD drives, taking out the video card and so on and every time I did, it took fewer "tries" in order to get the board to come on and stay on. When only the two motherboard cables were connected, it came on probably a quarter of the time after being off for more than 60 seconds.

- Edit -
In case it isn't clear, leaving it off for 60 seconds effectively reset my "tries" count to 0, only if I hit power as soon as it went off did past "tries" count for anything. In reality, I would guess that being off even 10 sec probably reset my "tries" count to 0, but I never tested this.
- End Edit -

From that, I deducted (correctly) that my PSU had lost the ability to supply the same amount of juice as it used to through regular aging.

I got a new (real) PSU (xfx core 650w) and I was good as new.

From regular aging, it is almost always the PSU that goes first. If a computer was working a day ago and isn't now, I would say it is at least 75% likely to be a PSU problem.

They just get old, losing about 10% of their effective wattage every year (not stated wattage on the pack). It makes a difference because more brands are like my old one (call it a 700w when its really a 300w) than the ones that aren't like that.

If my memory serves me, most OCZ PSUs have a multi-rail design instead of a fat single rail which means your PSU might be on a 16 - 20A rail while your video card is on a separate 16 - 20A rail instead of everything being on a single fat 40+A rail.

Those kind of PSUs aren't favored most of the time because they can't borrow from each other.

Imagine you have two rails with 20A each maximum and three devices that each require 12A to power. There is no possible way to configure this so that the computer will work correctly.

Compare that to a 1x 40A (instead of 2x 20A) where you can get 3x 12As on there and still have juice to spare.

It is possible that you were overloading one of the smaller rails like that.

The gameXstream has 4 x 18s (I just looked it up), so if this device is 1 or 2 years old those 18s could be putting out 16a or 14a, which may not be enough for your video card even if you don't have anything else on that rail.

I have a 4870 too and they use a lot of juice. If the PSU was 2 years old giving 14a (x12v) you would be getting about 168w off the wire at the most. I am quite sure a 4870 can pull more than that.

This probably caused the random shutdowns that you experienced, especially if it happened during gaming with newer games (this would make the video card try to max draw).

Alternatively, motherboards share their power with the graphics card (75w of it) with the rest for the video card coming through the 6 pin connectors on the end, so that 75 from the motherboard plus maybe 95w - 125w for your processor could have also blown right past the maximum amps on the motherboard wires as well.

Your problem sounds a lot like the one I had (even ok respected PSU brands still age) and it sounds like a PSU switch would fix it.

I would have suggested switching out the PSU before the motherboard if you had asked me originally because of these considerations.

Get an XFX Core 650w (excellent brand, fat single rail with 53a) and see if it doesn't fix you right up. My guess is 80% likely it will.

- Edit 2 - Sorry to tell you to buy a PSU off of an estimated 80% chance of success as well. I would hate to see you buy one and that didn't fix the problem. It is too bad that this is kinda the nature of the beast when you don't have good testing equipment or spares of everything laying around. It is possible the store will take stuff back if your computer still doesn't work after you try the new parts. I wish there was some kind of guarantee I could give you but there isn't.
November 17, 2011 6:42:06 PM

Raiddinn said:
I had a cheapy POS PSU (700w on the package but probably gave like 300w in reality) from years ago when I didn't know any better.

Well, it started having problems one day. I turned the computer off to give it a rest for a few days and it wouldn't come back on when I came back to it. More precisely, it would come back on, but only if I hit the power button again every time it lost power (which it always did within 1 to 5 seconds). After enough times (like 30) it would come on and stay on like nothing ever happened.

I started disconnecting things like hard drives, CD drives, taking out the video card and so on and every time I did, it took fewer "tries" in order to get the board to come on and stay on. When only the two motherboard cables were connected, it came on probably a quarter of the time after being off for more than 60 seconds.

- Edit -
In case it isn't clear, leaving it off for 60 seconds effectively reset my "tries" count to 0, only if I hit power as soon as it went off did past "tries" count for anything. In reality, I would guess that being off even 10 sec probably reset my "tries" count to 0, but I never tested this.
- End Edit -

From that, I deducted (correctly) that my PSU had lost the ability to supply the same amount of juice as it used to through regular aging.

I got a new (real) PSU (xfx core 650w) and I was good as new.

From regular aging, it is almost always the PSU that goes first. If a computer was working a day ago and isn't now, I would say it is at least 75% likely to be a PSU problem.

They just get old, losing about 10% of their effective wattage every year (not stated wattage on the pack). It makes a difference because more brands are like my old one (call it a 700w when its really a 300w) than the ones that aren't like that.

If my memory serves me, most OCZ PSUs have a multi-rail design instead of a fat single rail which means your PSU might be on a 16 - 20A rail while your video card is on a separate 16 - 20A rail instead of everything being on a single fat 40+A rail.

Those kind of PSUs aren't favored most of the time because they can't borrow from each other.

Imagine you have two rails with 20A each maximum and three devices that each require 12A to power. There is no possible way to configure this so that the computer will work correctly.

Compare that to a 1x 40A (instead of 2x 20A) where you can get 3x 12As on there and still have juice to spare.

It is possible that you were overloading one of the smaller rails like that.

The gameXstream has 4 x 18s (I just looked it up), so if this device is 1 or 2 years old those 18s could be putting out 16a or 14a, which may not be enough for your video card even if you don't have anything else on that rail.

I have a 4870 too and they use a lot of juice. If the PSU was 2 years old giving 14a (x12v) you would be getting about 168w off the wire at the most. I am quite sure a 4870 can pull more than that.

This probably caused the random shutdowns that you experienced, especially if it happened during gaming with newer games (this would make the video card try to max draw).

Alternatively, motherboards share their power with the graphics card (75w of it) with the rest for the video card coming through the 6 pin connectors on the end, so that 75 from the motherboard plus maybe 95w - 125w for your processor could have also blown right past the maximum amps on the motherboard wires as well.

Your problem sounds a lot like the one I had (even ok respected PSU brands still age) and it sounds like a PSU switch would fix it.

I would have suggested switching out the PSU before the motherboard if you had asked me originally because of these considerations.

Get an XFX Core 650w (excellent brand, fat single rail with 53a) and see if it doesn't fix you right up. My guess is 80% likely it will.

- Edit 2 - Sorry to tell you to buy a PSU off of an estimated 80% chance of success as well. I would hate to see you buy one and that didn't fix the problem. It is too bad that this is kinda the nature of the beast when you don't have good testing equipment or spares of everything laying around. It is possible the store will take stuff back if your computer still doesn't work after you try the new parts. I wish there was some kind of guarantee I could give you but there isn't.


Thanks for this post, that makes a lot of sense. The PSU is 4 years old, falling in line with what you were talking about. I'm annoyed I didn't come here first before parting with cash, hindsight is a bitch. As you say, the nature of the beast. I think I'll pop into a local PC shop and see if they can test it for me.
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November 17, 2011 7:14:59 PM

I would highly suggest you read this before any serious PSU decision making happens.

http://www.hardwaresecrets.com/article/Why-99-Percent-o...

It will help educate you about a lot of ways to avoid common pitfalls. The same website does a lot of good reviews and I always try to check that same page (hardwaresecrets.com) review site to see if they have personally tested that exact kind before I look at anything else when trying to assist people here.
November 21, 2011 5:52:40 PM

Well, much to my embarrassment I realised my RAM wasn't in properly. So now I have a display. I managed to log in and I was installing the software off the disc that came with the motherboard. I was sat in the other room when I heard the power just cut out. Now when I boot it I get as far as the loading screen for XP and then it restarts, gets the same point, restarts etc, etc. Any ideas fellas?
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November 23, 2011 5:42:16 PM

Blow away the OS again and reinstall it.

Also, invest in an UPS, they prevent a lot of stupid things from happening.

November 23, 2011 6:16:08 PM

Sound advice. It's a pain in the arse. I tried to install windows 7, then it started saying there was an issue with the DVD drive (removable media). Eventually managed to find out there were two bad sectors on the harddrive. I gave up in the end and took it too a computer shop, explained the situation. They have yet to call me back.
!