iMac won't turn on

I think I've had a virus attack. Last week the desktop was very slow, beach ball spinning, etc., then it would be be okay again. I used it earlier today and it was fine, but then it all started again. Despite shutting down, restarts, etc., now it won't even turn on. Can you help?

We can try to help but you have to help us help you. Please provide specs: Year and model iMac and which version of OS X you're currently running. And welcome to the Mac Forums.

Year and model and OS??

Since I can't turn it on right now I'd guess 2009 desktop iMac... know that isn't a great answer. OS 10.9 I think

Sorry for the deficiency of this reply, know it is not very helpful.

This machine has had NO problems since it came out of the box.

Last week had a pop up from Samsung that I had to take care of something right away. I don't have a Samsung, but my son had been here and possibly he'd connected to my computer/ that doesn't seem possible now that I say that.

I deleted that Samsung message, did a CleanmyMac.com run through (oh, right I must have had a problem once before since I had purchased that), had a friend tell me to download Malware something ... a very savvy guy ... all went well for awhile and all bad now.

Not a casual user, though it sounds like I am.

Is it completely dead when you press the power switch??

If so, and I assume there's no backup if you had any data worth saving, you'll need to take it to an Apple Store for their techs to check it out, or some local Mac tech that can do some checks.

when I press the power switch the gray screen comes up with the Apple in the middle, a circle starts spinning beneath that and then about 10 seconds later it all goes black again.

A friend just sent me this link to an article in CNN today: Watch out for these serious Mac attacks - Aug. 4, 2015

Sounds terrible. I think it may have happened to me.

Yes, I have a hard drive backup -- hope that will be the salvation. Thinking about calling APPLE and talking about this or packing up the computer and taking it to the nearest Mac place that fixes computers - about 60 miles away.

What do you think?

Have you tried booting it and using Safe Boot Mode??

Press and hold the shift key only when you hear that boot sound and until your see, hopefully, the progress bar or grey spinning gear, then login fig it gets that far.

It sounds like possibly a GPU or overheat problem. But it would have to be super plugged up and no airflow to go goofy and overheat in 10 seconds.

No, you don't have a virus, and no, you probably don't have malware. From your descriptions, it sounds like either a starting-to-fail hard drive, or CleanMyMac (junkware) is causing the issue. If you can, uninstall it (don't just delete it) according to manufacturer directions.

That Samsung alert does make me suspicious, however. I'm glad you dismissed that, it was likely fake.

Thanks for these replies.

pm-r
just tried the Safe Boot -- nothing better happened, can't get to the logins, therefore can't uninstall.
BUT -- you are right about possibly overheating. I now remember the fan running for a long time the other day. Now what?

chas
The CleanMyMac has been on my computer for over a year, so don't think that could suddenly be going wonky.

How do you know it isn't a malware problem ...

This doesn't seem like something we can solve here. Right?

I'd doubt that CleanMyMac is causing any harm as it's usually pretty dormant unless set to work by the user.

Do you have another boot drive you can use or try, or even another Mac you could try with using Target Disk Mode?

I called the Mac technician sort of nearby and he said it sounds like just what you said, a failing hard drive. Suppose you could say a failed hard drive, so an out of town trip seems to be upcoming.

Thanks guys for the support about the non malware influence. Must have just been a coincidence this all happened the same day.

If you've got any other ideas or suggestions please let me hear.

Can you start into Recovery mode, leave the Installer, go to Utilities and run Repair Disk?

Immediately after hitting thebstart button hold down Command and R key. Suggest being coming for a while with sluggish starts, beachballs etc. CleanMyMac, Mackeeper, AV software etc are of questionable value.

I talked with my son. When he was visiting he did attach his Samsung phone to my iMac as he was trying to download an executable file, a music play list, for me. The iMac rejected it, said it wasn't compatible. Now I'm thinking the Samsung notice that wouldn't go away did something to my machine and took awhile to screw some things up and completely has shut down the machine because of the incompatibility.

Taking it out of town later today to meet the technicians.