screen randomly goes black

hello again
there is one more problem with my imac! **** this thing it has like 1 million problems!
anyways the problem goes like this: the screen randomly goes black... i m just like chatting or i m on firefox and suddenly the screen goes black... no sound nothing just a black screen and i have to shut it down and then it works fine again...
anyways i went to the console messages and got these lines when the screen went black


8/3/09 2:01:20 PM [0x0-0x17017].org.videolan.vlc[157] [0x280338] main interface error: no interface module matched "globalhotkeys,none"
8/3/09 2:01:20 PM [0x0-0x17017].org.videolan.vlc[157] [0x280338] main interface error: no suitable interface module
8/3/09 2:01:20 PM [0x0-0x17017].org.videolan.vlc[157] [0x201768] main libvlc error: interface "globalhotkeys,none" initialization failed
8/3/09 2:01:20 PM [0x0-0x17017].org.videolan.vlc[157] [0x201768] main libvlc: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.
8/3/09 2:01:22 PM [0x0-0x17017].org.videolan.vlc[157] Interface initialization failed
8/3/09 2:01:22 PM com.apple.launchd[70] ([0x0-0x17017].org.videolan.vlc[157]) Exited with exit code: 1
8/3/09 2:01:32 PM [0x0-0x18018].org.mozilla.firefox[159] Debugger() was called!
8/3/09 2:01:55 PM [0x0-0x18018].org.mozilla.firefox[159] Debugger() was called!

and thanks....

Have you run Disk Uitilty and verified permissions and the HD?
If not, you should, but run it from the install disc.
If you don't have them try the fsck command. If you search here you'll find a "how to" about that.

thanks for the help mate...
i just did it...
but how is this going to help me with the black screen thing?? (i m asking in the best possible way)

Well verifying permissions etc and the HD may turn up some problems with the OS that Disk Utility can fix.
FSCK will almost certainly fix it if it's an OS problm, but this is a process of elimination, it could be a video card problem, or a loose connection to the screen, but start with software and then do hardware is my way of looking at it.
Did Disk Utility come up with any errors?
Do you have a Hardware test disc?

yeah i did both permission and disk check... the disk was ok although i had permission problems... but the thing is that i just had a clean install yesterday... i really hope that this fixed my problem... and thank you very much for the help...

and i have this problem as well

http://www.mac-forums.com/forums/apple-desktops/161021-imac-20-aluminium-problem.html

take a look at it if it doesn't bother you, although i restarted the nvram and it seems that this solved it... not sure though....

How old is your iMac? It can't be that old being an Aluminium model. Is it still in warranty?
I read the other thread and that's quite unusual and worrying, and certainly not right.
I would definitely run a hardware check now, just to see if it throws anything up, but it may be a power supply problem.

it is like 2 years old...
and the warranty was just for one year
and yes that was what i suspected.. do you think it is the power cable or something from the inside?

the thing is that i have only one installation disk which i think is the upgrade disk or something... so when i restart my mac and press the d button nothing happens...

angelo9888 said:

the thing is that i have only one installation disk which i think is the upgrade disk or something... so when i restart my mac and press the d button nothing happens...

Click to expand...

That's as it should be...pressing the "d" button will do nothing...you're supposed to hold down the "c" button if you want it to boot from the CD/DVD drive. Assuming your iMac will boot or can boot from this CD/DVD!

- Nick

pigoo3 said:

You're supposed to hold down the "c" button if you want it to boot from the CD/DVD drive...assuming your iMac will boot from this CD/DVD!

- Nick

Click to expand...

Not for the Hardware test, Angelo was right, and then it appears you don't have the right disc.
What OS are you running?

10.5.7 the installation disk is 10.5 though....

Kevriano said:

Not for the Hardware test, Angelo was right, and then it appears you don't have the right disc.
What OS are you running?

Click to expand...

Angelo mentioned having an "installation" disk...that as nothing to to with the hardware test...so holding down the "d" key will not help when trying to boot from an installation disk.

- Nick

pigoo3:

Intel-based Macs: Using Apple Hardware Test

Angelo, you need to read that too, just to check. If you have a generic leopard disc (dvd) you won't have the Hardware test built in.

yeah that's what i got... so what do i do now????

Kevriano said:

pigoo3:

Intel-based Macs: Using Apple Hardware Test

Angelo, you need to read that too, just to check. If you have a generic leopard disc (dvd) you won't have the Hardware test built in.

Click to expand...

Thanks for the info...but as I mentioned previously, "Angelo" never said anything about running the hardware test...but I do agree that running the hardware test would be a good thing to try.

Angelo also mentioned in the link to another thread that the computer is a 20" Aluminum 2.0 ghz iMac. The computer shipped with Mac OS 10.4.10.

Angelo also mentioned in this thread that the installation disk is OS 10.5. So my guess is the disk does NOT have the hardware test, or it's not a disk that came with the computer...so it may not even be a compatible disk for the computer.

So all this talk about hardware test is just a waste of time!

- Nick

That's why I asked what OS he was running, and whether he had access t a hardware test. It's only a waste to ask if you know in advance he doesn;t have it!
Anyway, this isn't solving anything.
Angelo, have you tried FSCK out of interest?

Kevriano said:

That's why I asked what OS he was running, and whether he had access t a hardware test. It's only a waste to ask if you know in advance he doesn;t have it!
Anyway, this isn't solving anything.
Angelo, have you tried FSCK out of interest?

Click to expand...

Yes...I saw that you asked "Angelo" if he/she had a hardware test disk much much earlier in this thread...but I don't think we ever got a clear answer to that question.

I only mentioned that the whole "hardware test" idea didn't seem to be getting anywhere, since the OP wasn't really responding clearly to that idea.

If the "OP" wants help...it would help out if they would properly reply to questions sent their way....so we can help.

- Nick

well the problem continues! and i really thought that i got rid of it cause it didn't happen all day long... anyways i didn't try the fsck thing but i m going to... i m starting to think that this is a hardware problem and not software cause i had to transfer the imac with the train to another city
and i think you are really helpful you guys thanks again...

angelo9888 said:

... i m starting to think that this is a hardware problem and not software cause i had to transfer the imac with the train to another city

Click to expand...

Considering the "flow" of the conversation so far...I assumed that this iMac was sitting on your desktop at home somewhere...and that you were trying out the ideas that we have been suggesting.

I'm not really sure I understand what you mean with what you said about "I had to transfer the imac with the train to another city"???

This has been a sort of confusing thread!!!

- Nick

hahahaha
what i m saying is that i had the mac to the city that i was studying and i had to transfer it back in my hometown cause my studies are over... and that happened like a week ago....
the problem appeared like 3 days ago....