Mac is messing up, not sure what it is

Not sure if this is the right place to put this. The past few days I've been having problems with my mac. LOTS. It's an iMac, about 3.5 years old, running Snow Leopard.

The past few days it keeps freezing, forcing me to restart. Music still plays, graphics freeze, mouse works. That's it. Sometimes the screen will just go black, but music will still play. It's done this probably 100 times in the past 3 days (no joke). I'm lucky if I get 2-3 hours out of it, around 1 hour average. Sometimes I restart and it does it again 5 min later. It's not a certain thing causing it that I know of. Sometimes it will crash with having nothing more than iChat, finder, safari and itunes running. Sometimes I also get graphical errors and artificats on screen. Little blue/green pixels, lines across the screen, mouse will look like a giant square barcode, things like that. Idk if this is a hardware issue? (which I hope it's not). Or what it could be?

Any help would be appreciated

Edit: Also, the mac is running unusually slow as well. My hdd was near full (20gb left), I delete about 40-50 to see if it would help, but it doesn't seem to be.

Edit2: Seems to be getting worse. Freezing every 5 mins or less. Mouse and sound froze as well the last time..

It certainly sounds like a hardware issue. Do you have your Snow Leopard install DVD? Boot your iMac with it and use Disk Utility to do a verify and repair on the hard drive. Let us know the results. I suspect your hard drive is failing so if you have not made any backups, do so as soon as you can.

See this article: "How to use Disk Utility"

I will try that tomorrow when I get home from class. When I check Disk Utility from the OS, the SMART status is verified if that's a good sign. What exactly is the difference between Verify Disk and Repair Disk?

Also, why do you think my hdd would be failing so soon? Not saying you're wrong, it's just really early for that sort of thing to be happening. Or any hardware issue really. The only thing that should be failing this early are videocards or the power supply if you do heavy gaming, but I don't haha.

Also as an update. This didn't start until I started playing Minecraft (online Java game if you don't know) a few days ago. It seems that the longer I don't play minecraft the longer it will stay running. I don't see how Java could have this much of an effect on the entire system? I've had it happen multiple times without even running Minecraft (or Java) from startup so it's not just due to that.

Whitey said:

Also, why do you think my hdd would be failing so soon? Not saying you're wrong, it's just really early for that sort of thing to be happening.

Click to expand...

You have to remember that it is still JUST a HD.No magic fairy dust to make them last HD's fail. Heard of HD's failing after only a month. It happens ...

Also as an update. This didn't start until I started playing Minecraft (online Java game if you don't know) a few days ago. It seems that the longer I don't play minecraft the longer it will stay running. I don't see how Java could have this much of an effect on the entire system? I've had it happen multiple times without even running Minecraft (or Java) from startup so it's not just due to that.

Click to expand...

My 1st suggestion would to be if it has it uninstall anything to do with MineCraft.
Then try and disable Java in whatever browser you have running. We can only try things one at a time to try root out the culprit.

As Charlie said, post back results so we can work on the next step

Cheers

Ok I haven't tried Repair disk off the install disc yet, but I ran Verify Disc in Disk Utility and it said it seems to be OK. What is the difference between verify and repair? It's not going to delete anything, is it?

Ok, I ran Repair Disk 3 times, each time it said the volume appeared to be OK.

Any other suggestions?

I'm gonna try going a few days without using Java and see if it's fine. I would never suspect Java to compromise the system like that though, especially on a mac.

OK. Thanks for posting back. Now that the hard drive seems to be OK, we can look to something else that's causing the problems you're having. I'm still convinced it's a hardware issue. Let's check out the graphics chipset. The next time it freezes or you get the messed up screen, take a screen shot and then look it over. If the screen shot is messed up same as what's showing on the display, then it's graphics related. If the graphics chipset is failing or intermittent, that would mean a logic board swap. Let us know.

Just a quick update. I don't wanna get too optimisitc just yet, but after repairing the disk, I haven't had any major problems. Some small graphical glitches a few times, but they go away too quickly to take a screenshot. But I've had the mac on since then, and have tried playing Minecraft many times. No freezing or crashing. And seems to be back up to speed.

Thanks guys for the help so far

Thanks for posting back with an update. Since your machine is over 3 years old, it's a good idea to keep up with backups. Hard drives do fail and usually without much warning. Have fun and let us know if you need any more assistance.

You should repair disk permissions every so often or at the first sign of a problem dont wait until you corrupt the system file.

Whitey said:

What is the difference between verify and repair? It's not going to delete anything, is it?

Click to expand...

When you verify a disk the software, Disk Utility or other programs, is checking for errors in the file structure of a disk. This is essentially looking for problems in the directory structure of the disk.

Repairing a disk attempts to fix the directory errors found during verification. Sometimes a disk has enough errors that the verification procedure must be run several times to fix all of the errors.

Neither of these procedures delete data from the hard drive. If data loss occurs it is usually because the directory structure was severely damaged.

Update:

I repaired disk permissions. There were a few errors with Java, so I'm guessing that's why it accelerated freezing so much more.

It took a few days, but I started getting graphical glitches again, slowly more and more, till it froze again. The artifacts do in fact stay in the picture when i take screenshots.

Posting an update. Still having a problem with this. Seems to happen more often when the computer is under heavy load. I mentioned before that I repaired permissions, however I've done this multiple times, and it always finds the same ones and "repairs" them. Though I doubt they're actually being repaired since they're back everytime I run it. Is there a way to fix this?

We're back to square one. Boot the machine once more with your install DVD and run Verify and Repair. Never mind repairing permissions. Let's see what it says. After re-reading this entire thread, I'm back to thinking that your hard drive is marginal. Hope you've been making backups as originally suggested.

Your machine is over three years old so it's not unusual to have a hard drive fail. Swapping out a hard drive in any iMac is not exactly easy but it can be done by using good instructions. Let us know.

I've made a few backups of some really important stuff, but I've still yet to get the bulk of things, I'm trying to borrow a friends external hdd for now being I'd need tons of dvds even to save all my stuff haha.

My computer started making a weird clanking sound last night as it froze. It was good to go after a few seconds again, but the noise didn't stop, so I just turned it off for the night. I'm thinking that may be hdd now too, cuz what else in a computer would make a sound like that besides fans?

It's a pain but I'm thinking of just replacing the hdd and starting over just in case before I lose all my stuff. I found a nice size one for pretty cheap too. And if it wasn't that, then I have a nice big new hdd with a fresh install of OSX

I've had the mac open before, so I know how to go about doing that, and it sure isn't a pc tower haha. The thing I'm more concerned about is installing OSX? I know one windows you'd have to go about setting up the MBR, format the drive, then actually install Windows. But what do you need to do on a Mac? And do I have to install Leopard first then Snow Leopard?

Thanks