Disk I/O error

Normally when a bad sector is reached you will get an in out error .. also a faulty ide controller will get you that but it will happen much more frequently in that case..

the symptom that it shows with specific programs is another sign that there might be a bad sector where the program resides .

run a S.M.A.R.T. check to see if it reports anything abnormal first
http://www.apple.com/downloads/macosx/systemdiskutilities/smartutility.html

I don't think rams can cause disk I/O problems ..and I also don't see why a logicboard change would help bad sectors go away if this is indeed caused by them .a rather easy way to find out is to uninstall adobe apps. and re install ..this will move them in different sectors on the disk .and if indeed you have bad sectors now the problem will finish/move to another app or something.

now important step to take is backing up your data quickly because bad sectors have a tendency to spread like mushrooms ..

Get your most valuable data out first and then the rest and yes you will need a new disk ..

I would like to correct some information, Murat. Please take this as what it is, just clarification.

I don't think rams can cause disk I/O problems

There's no question that it can't. Nor can changing the logic board. The drive is a physically separate component. If the drive is developing bad sectors, it is impossible for any other component to cause the problem. Though in a roundabout way, replacing the logic board could, but only in the sense that the technician who replaced the board may have dropped the drive.

and if indeed you have bad sectors now the problem will finish/move to another app or something.

Correct, but doesn't solve the issue. The bad sectors are still on the drive. Something else will eventually occupy that space. Then that file will not be able to be read.

To fix the problem, the drive must either be formatted with Disk Utility, or use of a third party application. With Disk Utility, you must first back up your drive as you will be erasing it. Run DU with the option to zero erase the drive. After each write, the drive will check to see if the sector can be read. If not, it is added to the bad sector map so nothing can ever be written to that area again. There is limited space for this information, though. If there are more bad sectors than can be cataloged, then the only option is to replace the drive.

For a non destructive approach, Drive Genius and Tech Tool Pro can scan the drive for bad sectors and map them out without erasing the drive. The only loss is if a live file is sitting on a bad sector. The software can attempt to move the file to a safe location, but don't count on it being able to.

bad sectors have a tendency to spread like mushrooms ..

Yes and no. A head crash, or just a bad surface that is flaking off can indeed cause a cascade effect. But I had a SCSI drive which developed bad sectors (a fair number) which were successfully mapped out. I had no further issue for the three years I continued to use the drive. Replaced only for a larger capacity drive.

The second half of your post I salute Kurt nothing but solid information ..However I think you have mis-understood the conversation earlier in some points, to clarify :

OP : I also suspect bad sectors. But why didn't it then help to change mainboard + cable
Me : I don't see why a logicboard change would help bad sectors go away
Kurt : It is impossible for any other component to cause the problem

We were talking about a LB swap fixing them not causing them

Me: a rather easy way to find out is to uninstall adobe apps. and re install ..this will move them in different sectors on the disk .and if indeed you have bad sectors now the problem will finish/move to another app
Kurt: bad sectors are still on the drive. Something else will eventually occupy that space. Then that file will not be able to be read

That's exactly what I said .I was offering this as a diagnose method to see if bad sectors caused the problem or not

Peace 🙂

it will be even harder to diagnose that .there is however a significant amount of speed difference ..I know in my time when I was ripping cd's when a cd didn't read a bit due to a scratch in slow speeds it would read (not using error correction bits) ..however they are two completely different types of media and I'm not sure if such comparison would help

We were talking about a LB swap fixing them not causing them...

Yes, my mistake in reading through the threads. Easier to see when you placed the comments together. 🙂 As you noted, it is of course impossible for a logic board swap to correct bad sectors. They have nothing to do with each other.

That's exactly what I said. I was offering this as a diagnose method to see if bad sectors caused the problem or not.

That's what I thought overall, but the one part of your statement caused a bit of confusion, where you wrote:

now the problem will finish

It's not clear what "finish" meant in the context of the sentence. I reads mostly like the problem then resolves itself. Which as I can now see you know, it can't.