pc display problem

I wasen't sure where to post this, so if im in the wrong place, sorry.
Here goes, Im having a weird pc problem, it started about a week ago when my computer simply stoped in its tracks (power is still on but the screen just goes black, the screens power light is still on but its like its not getting a signal from the pc.)
The next day it started happening every couple of hours or so, and its been getting worse ever since. Now when i turn it on the screen goes black right after the "windows xp loading" screen with the black backround. It does the same thing in safe mode.

First i tought it might be the video card, so i tested it on another pc and its fine. So i figured it was software related, so i tried reinstalling windows. It boots from the cd just fine, but when i get to the regional settings dialog it does the same thing again.

Can anybody help me with this, or can someone tell me what i should be looking for.
The pc is a dell minitower with windows xp sp2 installed. All of this started about 2 days after i instaled a new dim of ram.

Have you tried taking out the the ram you installed?

Quote:

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Originally Posted by Project2501

All of this started about 2 days after i instaled a new dim of ram.

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This is most likely the problem.....could be any of these

Incompatible RAM

Try removing the stick you recently put in and see if the problem comes back or disappears.

HTH

Quote:

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Originally Posted by MadBeaver

Have you tried taking out the the ram you installed?

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yep ive tried that, no luck

Quote:

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Originally Posted by Project2501

yep ive tried that, no luck

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Maybe you nudged a cable, try reseating all the cables and plugs.

Quote:

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Originally Posted by dalek

Maybe you nudged a cable, try reseating all the cables and plugs.

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ive tried that too, im getting pretty desperate

When you boot up, can you go back to "last known configuration"? give that a try, it could be a driver issue, also try going into "safe mode" this will load the minimum required drivers.

Hmmm,

1. Disconnect the screen from the computer and power it up, you should get either a diagnostic menu or a "no signal" display................. see how long that will last.

2. Check that all your fans are running, particularly the one in the power supply.

;)

Quote:

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Originally Posted by dalek

When you boot up, can you go back to "last known configuration"? give that a try, it could be a driver issue, also try going into "safe mode" this will load the minimum required drivers.

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ive tried both, nothing
in safe mode it does the exact same thing, the screen goes black right after the "windows xp loading" screen, ( i only see the "safe mode" writing in every corner of the screen for a second before the screen goes black)

Quote:

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Originally Posted by nihil

Hmmm,

1. Disconnect the screen from the computer and power it up, you should get either a diagnostic menu or a "no signal" display................. see how long that will last.

2. Check that all your fans are running, particularly the one in the power supply.

;)

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The screen is fine, ive tried it on another computer, when i power it up while its disconnected it just stays black, and the power light flashes. Thats what its always done when theres no signal.

OK they do vary................mine give me a "no signal" display or diagnostics/setup.............. at least you found another way to test it independently so we can rule that out.

Please look at your fans...............you should be getting quite a decent blast out of the PSU unit.

Also, get the monitor from the other machine and try that? I would expect that you will have the same problem...............please try another cable when you do this ;)

im not home right now so ill check the fans and try another monitor as soon as i get home,
thanks for the help

My thought is the original bank of memory has received static damage.

There is a utility, free for the download from microsoft. It is a self booting memory test utility. The Bios does not check ram when it boots, it only counts it.

http://oca.microsoft.com/en/windiag.asp

I just tried it with the other monitor and cable and i got the same result :(.

Its late, im tired, long day....
im gonna check the fans and test the ram tomorrow, ill keep you updated.
Thanks everybody for the help

OK................you may have a bit of difficulty running a memory test if it blacks out after a few seconds...............will it let you get into the BIOS setup?

A first try would be to remove the old RAM and just leave the new strip in there. Put it in the lowest numbered slot (0 or 1).

One question, as you get as far as starting to load Windows, the BIOS post has finished..............how many beeps do you get?

I just hope you haven't flexed the motherboard when you installed the RAM.

Ok so i tried the memory test this morning on each of the sticks but the screen blacked out on both of the strips.

All the fans are working properly.

Then something weird happened, i restarted the pc again to check "how many beeps" and it dident black out this time. The screen flashed twice during the windows startup. I had to leave for work so ill check it when i get home.

By the way it dosent beep when it starts up and i dont remember it ever beeping during startup before.

I dont think i damaged the motherboard, the ram slips in very easily.

I was thinking about testing the ram in another pc, but if the cause of the problem is the ram im woried it could damage the other pc.

Hmmm, you should get a beep code if you have a problem. Try going into setup and see if there is a setting for "beep codes", BIOS messages or whatever.

Here is a reference site: http://www.bioscentral.com/postcodes/dellbios.htm

As it is a Dell, it probably has a castrated BIOS. I would turn off "fast boot" and scroll down and read the "System Event Log", that might give you some clues.

You might also try booting with "step by step confirmation"

I was able to restart it this evening, the pc stayed on a whole 5 minutes before it blackout again :(

I looked at the system event log, the only thing it displays is the amount of memory changes from instaling and uninstaling the ram to test it

I was able to run the ram test without it blacking out, i ran all the standard and extended tests, "no erors have been found"

I turned of fast boot, i dont see anything in the setup for the beep code

i have windows xp so there is no "step by step confirmation"

Did your MoBo come with any monitoring utilities? I'm wondering what the heat of the processor is?

When the screen is "black" does moving the mouse or pressing any of the keys on the keyboard make the hard drive light? This could give a clue as to the problem being the video card, video could be out but the processor is still running the OS thinking that you have a display.

On your monitor does the power on light change colors?

You got past the memory issue. This is starting to sound like a bad processor or even a bad power supply.

Well, if it gets into windows then it isn't a post problem.

It seems to be temperature related..............are you overclocking anything?

It could be the PSU or even the processor, but I would suspect a motherboard/ dry joint issue, given that it started to happen right after you changed the RAM.

If your video card supports TV out you might try running it on a TV?

The motherboard dident come with any monitoring utilities, but ill ckeck Dell's website just in case.

When the screen is black, theres nothing going on with the pc, nothing respond (mouse or keyboard). Its on a router with another pc and when the screen goes black the pc stops responding. The power light is on and the fans spin, and thats it.

On the monitor the power light starts flashing, it does that only when it dosent have a signal (it turns yellow in sleep mode).

Im not overclocking anything.

Whats a dry joint issue?

I already tried running it on a tv, the screen whent black after a few minutes.
Ive also tried removing the video card an only using the built in video adapter, same result.

Im starting to think that maybe i cliped or crushed a wire, , cause the case "folds open". And everything is pretty much a tight fit since its a its a mini-tower.
http://apcdigital.com/catalog/images/gx280MiniTower.jpg
Ill check all the wiring again tonight.

OK a "dry joint" is a soldered connection. Over time they become brittle and crack, particularly if you put any sort of stress on them. This tends to produce intermittent faults due to expansion and contraction with temperature fluctuations.

I notice that the tower has some sort of CD/DVD drive on it. When it "goes black" again just try the button and see if the drawer comes out, and will go back, and the little light flickers.

I am curious to see what is still getting power.............as those drives have a direct supply from the PSU via a Molex connector, it might indicate if it is a PSU problem.

Otherwise I wonder if there isn't some sort of chip on the MoBo that handles the communication between the CPU and the video output? It may be having difficulties?

If you set Capslock and Numlock on, do the lights on the keyboard go out when you get the black screen? The keyboard gets its power via the MoBo.

Dry joint... I'm going to have to remember that one. Thus side of the pond they are referred to as a cold joint. The same thing different name. Usually happen during the manufacturing process, something shakes or moves before the joint has totally solidified. They can be a real b**ch to troubleshoot. Sometimes you can use a can of "freeze"

Yep the dvd drive works great, opens and closes and the the light flickers too.

I turned on caps an num lock, then at the windows loading screen the monitor flashed and both lights whent off, num lock came back on after a few seconds. So i turned caps back on. When the monitor blacked out for good, both lights stayed ON.

Small orange light in the middle of the MoBo is still on, and network card light is still on. Harddrive light is off ( but its not spining)

Usb ports still have power, but no connection can be made with peripherals.

So it sounds like the power supply is doing it's job, you've got 5 volts as the leds are working, you've got 12 volts - the drive ejects.

At some point in the troubleshooting process, we need to start swapping things. Do you have any spare (junk) computers to borrow parts from? If you could swap the video board that would be the easiest to try first.

I'm not saying you should buy a new video board yet, the original may still be good.

If it was a heat problem, you could try a product that's available at most electronic stores. It's a liquid nitrogen spray that cools components. You have to be careful because going from 200 degrees F to -200 can destroy a component as well. You could gently spray into the fans input on the processor or into the video board. One approach would be to choose a component and only apply to that component prior to shutdown and see if you can keep it alive. Another approach would be to cool a component once you've suffered the shutdown.

Hi ddddc, and a happy Easter to you and yours :)

I think that we can rule out the video card here as it works on another machine. Also he took the video card out and used the onboard video chipset and got the same problem.

I wondered about the connection, but we get the same problem with video card, onboard video and TV out..............so it can't be that.

The power supply seems OK from what we have tested, but I don't know about the 12v supply to the MoBo as it is on a different rail AFAIK. If I had the box on my bench, I would disconnect the power from the MoBo, fire up the PSU for about 10 minutes then meter the outputs.............actually I don't normally even bother with that, I just connect a known working PSU as I have several to hand :D I would get the PSU tested just to be sure that it is working properly.

I guess that then leaves us with the MoBo and the processor?

My first move would be to remove the heatsink and fan and clean them thoroughly. Then clean off the old thermal paste and replace it with a silver based one. [Follow the instructions carefully: you can have too much as well as too little] When replacing the heatsink and fan assembly, make sure that it is properly aligned and firmly seated.

At this point you need to think about the economics. If the above doesn't work then take the processor assembly to a repair shop and ask them to test it?................ if it is OK, then just replace the MoBo.............it is not economical to get them repaired unless it is something obvious like a damaged connection loose wire or whatever.

Ill try changing the psu with my other pc to test it when i get a chance .
Ill keep you posted.
Thanks again

i have had problems with my network card. it kinda did the same thing. except the screen didn't go black. when i enable it and try to do something else the whole computer locks. the drives worked but the keyboard lights stayed on. even the lights to card worked. i downloaded an updated driver for and the problem ceased. the problem was that there were some conflicts with the mother board. minor fix. yeah right. u recently installed some ram there could be conflicts with the mother board. im not an expert. just an experienced beginner. :D but it seems that somethings conflicting and its involving the monitor.

Well, the answer to that is simple. Just physically remove the network card if you can. If it is onboard then disable it using system manager (save a hardware profile first;))

Might as well unplug the DVD as well (just the Molex) so it isn't drawing power. I don't really think that it will do much, but it would only take a few minutes to try?

i think i just found my problem.
When i plug in the power cord in to one of those mini-tower, the fan in the psu starts up full blast for about one second. Its like a car doing a rev, always tought it sounded kinda cool :).
I just notices it dosent do it anymore when i plug it in, so im gesing its the psu :(.
Problem is ,since its a mini-tower, the psu is a custom shape, ikinda like this:
http://cgi.ebay.com/BRDNEW-DELL-DIME...QQcmdZViewItem

To bad, cause i happen to have two standard psu.

oh well

It sounds like the PSU has a thermal sensitive fan. In the quest for quiet some manufacturers put a demand circuit in, the fan runs slower when things are cooler making less noise. As something heats up then fan speeds up, but makes more noise.

I don't know how much the new fan is going to cost you but if you hunt deep enough you can probably get an ATX case and PSU for about $40.

Of course the Mobo has to have the same form factor as the case, unless you want to get into modding. ;)


My processor fan "hunts" for the correct speed at startup, it sounds like a race car revving up through the gears.

I would still try to connect one of the other power supplies and see if it works with that. Standard PSUs would have longer cables so you should be able to do it.

:)

Try using the onboard display if your mobo supports it..I know you said you have tried the screencard in another pc..Also try setting your cmos config back to default and try again..You could also try and take all your extra cards if you have some out like modems,sound,lan etc and just leave your screen connected to your onboard screen port or if you do not have one then leave your screencard in..Also try another slot for the ram if possible or even a different stick of ram..What is your ram config..?2x512or 2x1gig or 1gig??

Ok, so before i started swapping stuff i tried starting it up again, now it wont start up at all the power light comes on and the fans but the screen is black.

And now it beeps 1 second after powering up???

So i swaped the psu with one thats exactly the same from my other pc (both are the same model) by the way the psu is 160w and all the adapters are custom made for the mini-tower. It still dosent work. I tried that psu in the other pc and guess what, its working just fine. (good news i guess since i dont have to go psu hunting)

Ive noticed one thing do, the fan that makes the rev sound when i plug it in, isent the psu fan as i thought, its the cpu fan ( but its working great when i turn the power on). <----im guessing this is related to my problem somehow

Ive checked all the wiring, everything looks good.

Everything is getting power.

Ive tested the ram

Ive tested the video card, ive tried the tv out, ive tried the onboard monitor adapter and ive tried using another videocard (the exact same model).

Ive got nothing else to disconect from the pc since the network card is built in, theres no modem.

The CPU fan is usually a temperature controlled fan. Speeds up when the CPU gets warmer.

You've ruled out:
The monitor
the video card
the power supply
It sounds like the MoBo and or the processor is bad.

Depending on your location you could probably get a replacement MoBo and processor relatively cheap as a package. Windows XP will complain because it will think you've made a pirate copy (it will sense the hardware change), a phone call will get you a code to fix that.

You could get a faster board/chip. Make sure you get the right form factor and match the RAM type so that you don't have to replace that too.

OK Maybe I am in a constant state of denial...........in post #27 I had reluctantly come to the conclusion that we had a processor/Mobo problem........

I have this kinda "gut feel" that it is the MoBo? The fact that the timings keep changing as you rummage around inside the box just seems to suggest this?

If it were the CPU I would expect a consistency, or a slow deterioration?.....

I would say a dry (cold) joint issue............ when I worked in the armaments industry I would have taken it in for the guys to fix for me.

I think that ddddc is probably right, there are some pretty good CPU/Mobo deals around.

Your problem is that you have a mini tower............ a 160W power supply?

I have lightbulbs that use more:eek:

My advice would be to trash the machine but recover all parts that could be used to support the remaining one.

I am sorry that we were not able to provide a "happy ending" in this case:mad:

One last attempt? lift the fan and heatsink assembly..............clean them carefully, and clean the contact between the heatsink and the CPU...... replace the thermal paste with a silver based compound. Be careful to FOLLOW THE INSTRUCTIONS you can put too much on;)

Good luck mate!