Corruption problem

Teaf

Teaf

Teaf

Soldato
Joined
17 Dec 2006
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Just bought and put together a machine, specs are:

Intel E2200
Gigabyte P35-S3G
Sapphire HD4850 512MB
Corsair XMS PC2-6400 800Mhz

Was fine when I was installing Windows Vista. However I went back to the machine after leaving it on for a while and Windows was severly messed up. At first I thought the machine was struggling to load everything back in so I turned the machine off and then back on and there is a lot of corruption.

There are "dots" all over the screen on the POST Logo screen. The BIOS itself has other letters in place of the ones that should be there... such as instead of saying "Advanced BIOS Features" it'll say something like "Agydnvced BL!E FeamtZse". The POST screen is the same. Windows is fine when the graphics drivers are not installed, however as soon as they are installed Windows completely messes up.

I'm thinking the graphics card is dodgy, however can a graphics card change the letters in the BIOS, POST screen and even the Q-Flash built in BIOS utility? The "Logo" POST screen is the only screen that I got dots appearing on, other screens only have garbled text.

Any ideas?
 
The graphics card cannot change the letters on the screen, it's too low level for that. Could be a motherboard virus perhaps or physical damage to it. I'd guess it needs an rma, could try flashing it as a last resort.
 
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4850's run very hot - check that first.

If it's fine, then you're looking at running atitool and checking for LOAD temp and artifacts.

However, because stuff is being changed in bios, I'd probably go ahead and assume that your BIOS needs to be flashed. Problem is, if the machine isnt stable you could permanently screw your board up.
 
Energize said:
The graphics card cannot change the letters on the screen, it's too low level for that. Could be a motherboard virus perhaps or physical damage to it. I'd guess it needs an rma, could try flashing it as a last resort.
Click to expand...

Yeah had a feeling that the graphics card couldn't do that - so my next assumption was motherboard. I've just tried installing the drivers again for the ATI HD4850 using a different version (old hotfix drivers that I use instead of newest ones from ATI site) and they installed, I rebooted, and it says that the device couldn't be loaded as the drivers might be corrupt... so I'm thinking dodgy PCI-E lane maybe.

Going to try to flash the BIOS now, somehow at least... letters are totally all over the place.


4850's run very hot - check that first.

If it's fine, then you're looking at running atitool and checking for LOAD temp and artifacts.

However, because stuff is being changed in bios, I'd probably go ahead and assume that your BIOS needs to be flashed. Problem is, if the machine isnt stable you could permanently screw your board up.
Click to expand...
Checked GPU-Z and the card is running at 50c idle across the board. If the board screws then I'm not bothered, it'll be going back as DOA.


Cheers chaps, will report back when I get it flashed.
 
The manual should give you a picture of the bios screen allowing you to flash it even though the text is messed up.
 
Ah, here's my theory:

If the letters in the bios are different each time, then it is -not- bios corruption, rather something very unstable and storing characters wrong.

If they are the same each time, it's a good bet that when the board's bios was introduced onto the EEPROM chip, there was some issue that caused text to scramble. A bios flash should fix this.

Unfortunately, as windows takes over the low-level system functionality, any corruption in windows simply cannot be solved by a bios flash.
 
Flashed the BIOS - no change in the corruption.

So, I used my spare PC which has a Gigabyte G33M-S3 in it. Removed the motherboard and changed it all over, took about 45 minutes in total. Booted it all up and it was totally fine. About 2 hours later, PC hanged and I forcefully turned it off. Turned it back on and had corruption.

The only parts that were in both machined were

Memory
Hard Drive
Power Supply
Graphics Card

The problems are (exactly):

POST screen (and POST screen only - whether it's the full screen logo or just the regular text info) always has dots on it all over the screen. The dots are like colons " : " and are coloured yellow. They are about 1.5cm apart and cover the whole screen. The POST screen never has garbled text. The BIOS however does have garbled text, however only about 30% corruption on the text.

Moving past post and onto the boot phase, the text is fully corrupted. Words like "Validating" turn into "Vekdpaldnt" and nearly every word is random nonsense. Some words are still there. The words are always the same, such as "Validating" will always be "Vekdpalnt".

Windows, only when graphics card drivers are installed, has major issues. The screen is fully black to start with other than the password bar for Vista. Typing password and moving into Windows - it only displays half of it. If you open "Computer" you might get half the window appearing, if you drag and move it around you get portions of it appearing and disappearing. There are also about 2 - 5 large black horizontal bars going across the screen - depends on resolution. Note, this is only when drivers are installed, when they aren't installed it seems fine and there is no corruption in Windows.



So... what is causing it? It can only be graphics card, memory, hard drive or power supply and one of those components has to be able to garble the boot up text and display "dots" on POST. These problems have only started to happen on both machines after a couple of hours, so it's not an instant thing. I'm thinking that the power supply is ruled out in this case, because if it was the power supply it'd always be happening. I'm also pretty much ruling out of the hard drive because the garbled text at BIOS / POST happens even without the hard drive in and there's no way I can think of that a hard drive can alter BIOS/POST text like that, or cause dots.

This would leave memory and graphics card, and if I had to pick I'd say graphics card due to the graphical corruption (dots at POST and large black bars in Windows) - plus since it only happens after a couple of hours it could mean the card is taking a while to heat up since all I've been doing is sitting in Windows, and it might only be happening when it gets to a certain temperature.

This is of course my theory, I'd appreciate some others, as my theory contradicts what Energize said about graphics cards not being able to alter the boot up or BIOS text. Also just to note the text is always the same, such as "Boot from CD..." is always "Boej pqme FQ..." even after several restarts or turning the machine off then back on.
 
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Have you tried using the corrupt motherboard in the working machine? Something may be causing damage to the motherboard such as a rom virus. I would run memtest86 on the ram to check that. It could also be the cpu fetching data from the wrong memory address causing the wrong characters to be displayed.
 
Energize said:
Have you tried using the corrupt motherboard in the working machine? Something may be causing damage to the motherboard such as a rom virus. I would run memtest86 on the ram to check that. It could also be the cpu fetching data from the wrong memory address causing the wrong characters to be displayed.
Click to expand...

Cheers, will try memtest86 today to rule that out. The corruption happens on both motherboards after a few hours, also the CPU's are different, corruption happened on a E2200 and a E2180.
 
Just by you saying there were dots all over the post logo points to a graphics card related issue.
But the non random text in the bios is a good one.

You have 2 systems one fully working right ?
Try swapping over just the graphics card
 
Mick-1965 said:
You have 2 systems one fully working right ?
Try swapping over just the graphics card
Click to expand...
It's hard to try because it only starts happening after the machine has been on a few hours, but I'll give it a whirl when I do a memtest - as after a few hours even in memtest86 I'd imagine it would have went "funny".
 
Ran the machine with the old 7600GT I have and ran memtest86+ for 30 loops and there was no errors and no corruption at all. I've got an RMA for the graphics card, so hopefully that'll be that. Never knew that a graphics card could change text on a POST and BIOS screen... learn something new everyday :p

Thanks for all the help guys.
 
flibby,

I'm having the same problem here. Alas, it happened after 2 months of fine use. I can't have an RMA on it. I've contacted the seller for a repair, but not a reply until now.

My problem is the garbled screen on BIOS screen, DOS prompt, and Vista. In BIOS and DOS prompt, characters are readable but there are strange characters in some places changing colors now and then. Curiously, in DOS prompt screen, the strange characters move up one line at a time as I press Enter, just like what normal characters would do. It is like they have memories. I think that this problem could be memory related (overheating?) In Vista, there are small boxes in various colors all over the screen. Some heavy 3D games will load but immediately close themself and return to desktop. A light 3D games will load but with the boxes.

I 'am using Asus HD4850 with ATI reference cooler on Abit F-I90HD motherboard with 2x1GB and 2x512MB PC5300. I don't think that the motherboard and/or RAM are the problem. I tested the motherboard using its onboard VGA, and it worked fine.

I've been using the card for 2 months and it worked fine until recently. The screen is normal but after a few minutes, it is garbled. As the garbled screen also occured on BIOS and DOS prompt, I think it is not driver related. And as the garbled screen starts after a few minutes, I suspect that the problem relates to overheating. First question then, graphic core or graphic memory overheating? And second question, why now, after 2 months of usage?

To localize the cause, I modified the 4850 BIOS. Modification includes downclocking graphic core and graphic memory clocks to 250MHz and 264MHz (normally 625MHz and 993MHz), lowering voltage, and adjusting fan duty cycle to higher percentage. The core temperature is lowered but still the garbled screen. So, it may be the memory overheating. The possible answer to the first question. No memory temperature indicator to verify this, though.

I opened the heatsink and saw that the graphic core had thermal paste on it while the graphic memory chips had thermal pads. That was quite unusual for me. I had a 8600GTS using only thermal paste on the core and memory chips and never failed though it reached 75 degC under load. For long term performance, I trust thermal paste but I'm not sure about thermal pads.

Thermal pads are used in HD4850 with ATI reference cooler because the memory chips' height are lower than the graphic core while the heatsink contour can't fully eliminate the gap. I wonder if the thermal pads have failed after sometimes of usage causing the memory chips to overheat. The possible answer to the second question. In an addition to that, in the past, this card's core had reached 95 degC a few times playing heavy 3D games, which may further damaged the thermal pads as the heatsink heated up.

Soon after seeing what were under the heatsink, I ordered thermal pads to replace the current ones used in my 4850. Not many online shops selling this stuff, though. But I managed to find one. The products I ordered were Cooler Master Gap Filler (Thermal Conductive) Pad and Sekisui #5760 (thermal tapes), not sure which one will work.

I'm waiting for the thermal pads now. I would post the result, if anyone in this forum is interested.
 
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Thanks for the reply, interesting to see other people unfortunately getting this problem.

I just received a replacement graphics card this morning. Put it in, got half way through installing drivers, then the machine gave up the ghost and I got a screen filled with artifacts which were different colours and the monitor turned off (however the machine was still on). I highly doubt two cards in a row would have the same issues? If not them I'm wondering if the PSU is a bit iffy. It's a OCZ StealthStream 500w.
 
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Have you tried different memory as well? I know memtest came out ok, but it may still be dodgy, but as you say, it could also be the PSU as you say, if that's the case, you need to take it out asap, due to the risk that it could be permanently damaging your other equipment and try your working one (from your good pc). PSU's SHOULD sacrifice themselves for the rest of the computer, it's how they are designed, but if they are manufactured wrong then they can be giving the wrong voltages.
 
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Thanks for the reply!

Changed the PSU for a different one and got some square dots appearing on the desktop, but as yet nothing is corrupt pre-Windows. After getting the dots I changed the driver from the hotfix drivers to the newest ones and currently haven't got an issue and I'm running the artifact scanner on ATI Tool for a while to check. I've also did a full length hard drive scan with HD Tune and every block is green.

If I get no joy with the new drivers and new PSU I'll be trying the RAM out of my main machine in it and testing that.

Question... I've noticed that the sapphire card I have has a modified BIOS, it's not the stock normal bios that has 500/750 idle clocks, and instead has something like 100/250 when idle. Could this be a reason why it's causing issues? Maybe because the card's clocks are just too low?

Just trying to think what else could be wrong.
 
Most new cards these days have 2 sets of clocks, 2D clocks and 3D clocks. Kind of like the Intel speedsteep where it reduces the CPU speed when idle to reduce power consumption.
 
fobose said:
Most new cards these days have 2 sets of clocks, 2D clocks and 3D clocks. Kind of like the Intel speedsteep where it reduces the CPU speed when idle to reduce power consumption.
Click to expand...

Aye :)

What I'm thinking though is that the idle/2d clocks are way to low on this card, as my main machine's idle/2d clocks are 500/750 but this new cards idle/2d clocks are 100/250.
 
I just googled for "sapphire 4850 idle clocks" and one review shows your card (I think) with 160MHz idle rather than 100. :/
 
fobose said:
I just googled for "sapphire 4850 idle clocks" and one review shows your card (I think) with 160MHz idle rather than 100. :/
Click to expand...

Yeah sorry it might be 160, I took a guess. Just checked the machine and the default clocks are 160/250.
 
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