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Abbo · Joined: 02 Oct 2006 Posts: 25 Location: South Staffs

Hi,

I've been having a few problems with my computer over the last few months. It seems to like running the chkdisk a fair few times and occasionally I'll get these strange lines of colour appear over the desktop screen.

I've been on been on various forums and run different scan programs but still not got rid of the problem. Is it time for the computer to go and visit a computer doctor to rip it apart and have a proper look and what's going on?? Confused

NickAskew · Moderator Joined: 03 Nov 2006 Posts: 112 Location: Thirsk

Hi Abbo,

One of the reasons computers will attempt to run ChkDisk is if they feel they have been powered off without shutting down properly. You can simulate this easily by switching off your computer using the power plug off switch whilst windows is running. The fact yours is doing this all the time would make me wonder whether your computer is shutting down correctly on its own - do you choose shutdown or hibernate? Does it power itself off or do you have to switch off the power switch once it says 'it is safe to turn off your computer' or does it just lock up part way through shut down and you terminate it by pressing the power button on the front of the computer or flicking the switch off at the wall?

What kind of coloured lines are you getting on your monitor? (red/yellow/green/straight/wavy/2 of them, 3 of them, random number of lines?)
What type of monitor is it? (CRT - one that looks like an old TV, plasma or LCD/TFT)

I have seen a graphics card go bad and cause greenish bands of colour to mark the screen horizontally.
I have seen a graphics card go bad and cause either thin black or thick red bands to stretch vertically down the monitor.
I have seen green bands which flicker on and off randomly in approximatelly the same position on the screen which was resolved by updating the drivers of the wireless network card (which lead me to believe the older drivers that were being used were causing the network card to attempt to share memory reserved for the graphics card)

So, have you updated/downgraded any drivers for any piece of hardware on your computer since these lines appeared? Have you tried connecting your monitor to a friends PC to see if it shows lines still? (proving it is the monitor)

if your monitor only acts like that on your computer, I would be tempted to pull out all other none essential hardware (sound card/wireless network card/tv decoder/video encoder etc) and see if the lines disappear, if they do then I would plug each item back in one at a time and turn on the computer to see which one is clashing with your graphics card.

If you are using onboard graphics on your motherboard, the lines may be caused by memory that is going/gone bad - this may also influence the shutdown process and cause your computer to run ChkDisk all the time..

If you see any pattern to any of the things that are happening to your pc, then give us the symptoms and we'll have another think about possible causes.

Good Luck!

Nick

Abbo · Joined: 02 Oct 2006 Posts: 25 Location: South Staffs

Blimey!! So much to take in! Shocked

I'll try and keep a log of events etc. We tend to power down using the 'Start' - 'Turn off computer', the only time the computer hibernates as such is when we're worknig on something before 'tea' or something interrupts, so we leave the computer on and then go back to it after and move the mouse, but that tends just to be the screen turning of as opposed to the whole computer, but I'll try and log such times down.

As for the bands of colour, these aren't there all of the time, just every now and again adn even then when you start using other programs they don't always appear? They tend to be multi coloured (from what I remember, I'll pay more attention to them next time) and tend to be made up of a number of thin straight lines in about 1" blocks running vertically down the screen. The monitor is a 17" Dell Ultra sharp TFT digital monitor and looking at the device manager uses 128MB DDR ATI Radeon 9800.

I can't think of any hardware that I've updated/downgraded since the lines appeared; trying to tie down as tto the exact time they appeared is one thing. It seemed to hapen at a time when I got 'downloader' virus, but also I'd changed ISP to BT and installed the home hub and also I upgraded my AV software to Norton 360. The only actions I done since is running several scans using different software, to see if I'd got rid of 'downloader', removed Norton (but reinstalled it later) and removed the BT 'desktop help', because I beieved that was causing part of the problem (especially after a conversation with one of the BT IT guys!) This did seem to help for a while, but the lines have come back again?? Whether this is because BT have sent the update to the home hub software in the last few weeks???

I've not tried the monitor on any other computer, but as I've said because the lines come and go I hadn't suspected the monitor. I've looked in the device manager to see if it shows any conflicts but I can't see anything.

Excuse my ignorance, but when you say am I using onboard graphics on the motherboard... how would I know?

As I said I'll try and log stuff down and see if any patterns are formed??

Thanks again.

thescruff · Moderator Joined: 03 May 2003 Posts: 4249 Location: Bath

Cannot say if its relevant, but the Downloader virus was one of the ones that norton flagged up on my computer the other day.

I found it in the BT program although I don't use BT, it was built into the computer when new.

I deleted everything with BT on it and the virus has gone Rolling Eyes

NickAskew · Moderator Joined: 03 Nov 2006 Posts: 112 Location: Thirsk

Hi Again

The fact you said you had a 128MB Radeon 9800 tells me you are using an add on graphics card rather than one provided directly on your motherboard Very Happy

Ok there is nothing jumping out at me as a definate cause, however having had another think I wonder whether the chkdsk and banding are linked.

Do you ever turn your computer on and find you can't hear the hard disk start up at all? no noise, so you turn it off and then back on again and it then starts up as expected? I had a quick google and found several people having the banding issue with Radeons which they eventually put down to a failing power supply - a failing power supply might also cause you to have more disk errors than usual owing to the fluctuating current. Do you find the banding ocurrs more when the PC is doing graphically intensive operations such as rendering game graphics? Does it do more banding when the PC is cold or hasn't been switched on for long? Is it particularly cold in the room where you use the computer? Have you had any power cuts recently that may have pushed your power supply over the edge?

Are you in a position to borrow a friends computer power supply? If not, can you unplug any USB devices which get their power from your PC, this includes Flash(thumb) Drives, external hard disks, web cams and then use your computer for a length of time where you would expect to see the lines? If you have multiple hard disks inside your pc, is it possible to unplug every one except the boot disk? - Anything to lower the power consumption of your to see if it influences the problem.

I agree the BT help software is rubbish but doubt it would cause the issue. A virus might cause the behaviour your pc is exhibiting but I'm inclined to doubt that as well.

Cheers, Nick

Abbo · Joined: 02 Oct 2006 Posts: 25 Location: South Staffs

Hi Nick,

In reply to your message, I can't remember a time where I've turned the computer on and it's not sounded like it's booting up, if anything quite the opposite, I had a time where, when it was first turn on, it made a louder noise than normal, but that would often die down after a short while.
The banding tends to occur on the initial start up mainly, but occasionaly, say for instance I decide to play 'Spider', it sometimes comes on the screen then, but other than that, it's just mainly the desktop. I have noticed that the icons occasionally take on 2 mini horizontal 'bar codes' top and bottom, as does the arrow pointer, when on the desktop. (again it's not happening all of the time) I have a picture in the centre of the desktop which also tends to take on multicoloured fine dots? It does tend to be happening more often when the computer is first turned on or hasn't been on for long, but the room itself isn't particularly cold.

The only things connected to the computer via usb are: the printer but that's often turned off, the scanner, which is often just in standby, a card reader, a pda cradle and an extension cable for flash drives, which again are only used every now and again. The usb external hard drive only tends to get plugged in when I want to back stuff up. Is it sufficient to pull the plug to the peripheral rather than rummaging under the worktop to get to the back of the computer, or is it best to disconnect the cable direct from the computer, to test it? I haven't really got the time to start ripping the computer apart to try out different power supplies at present, so that option is a bit of a no go.

NickAskew · Moderator Joined: 03 Nov 2006 Posts: 112 Location: Thirsk

Hi Abbo,

When you get the time or the inclination, I would try these options in this order:

1) Different Power supply
2) Different Graphics Card

Cheers, Nick