27" iMac (late 2009) freezing

[evillageprowler]

Since perhaps a year ago, my aging iMac had been freezing about once every 3 months or so.

The exact apparent symptoms are that I get no meaningful response from keyboard or mouse, but the screen turns on. I would be forced to power off my computer and then power it back on.

Then the symptoms started appearing with much greater frequency starting a few months ago (perhaps early this year) ... now around two or three times a week.

Are there any diagnostics I can run? I think I don't have my original HDD (replaced maybe last summer?), but everything else is original or 3rd-party (I think I added additional RAM to my machine).

Any suggestions? I was tempted to buy a new 21.5" iMac today, but one with 512GB SSD is getting pricey so decided to hold off and try to squeeze more life from my existing device.

TIA,

EVP

 

[DeltaMac]

Does the non-responsiveness happen only during boot?
Or, do you get lockups/freezes during normal use?

Wireless keyboard/mouse, or wired (USB)?

 

[evillageprowler]

Does the non-responsiveness happen only during boot?
Or, do you get lockups/freezes during normal use?

Wireless keyboard/mouse, or wired (USB)?

Thanks for the reply. The freezing happens seemingly during idle -- I leave my iMac on all the time.

And, I have wireless kbd+mouse.

I will try running HW diags now: https://support.apple.com/en-us/HT201257

Wish me luck in finding out something.

EVP

 

[DeltaMac]

Thanks for the reply. The freezing happens seemingly during idle -- I leave my iMac on all the time.

And, I have wireless kbd+mouse.
...

Is your iMac at idle? (Is it sleeping, or NOT sleeping)
Do you see the desktop when you realize that it is frozen?
Notice if the clock has stopped, or if it is showing approximately the correct time? If that is not obvious, you could wait a minute or two, just to see if the clock updates...

Be sure to run both the standard and extended hardware tests.
Unplug ALL external devices (if any) when you run the tests.

Something that I will ALWAYS check, is to make sure the cooling vents are clean and clear. Particularly the small round vent under the hinge (above the power cord). That's a place that can directly affect cooling, and lots of folks miss it

 

[evillageprowler]

Is your iMac at idle? (Is it sleeping, or NOT sleeping)
Do you see the desktop when you realize that it is frozen?
Notice if the clock has stopped, or if it is showing approximately the correct time? If that is not obvious, you could wait a minute or two, just to see if the clock updates...

Be sure to run both the standard and extended hardware tests.
Unplug ALL external devices (if any) when you run the tests.

Something that I will ALWAYS check, is to make sure the cooling vents are clean and clear. Particularly the small round vent under the hinge (above the power cord). That's a place that can directly affect cooling, and lots of folks miss it

My iMac does not sleep. I run a web server off it (but willing to move it to a VM hosting site that is cheap), so it stays up constantly. My screen, however, does go off to save that bit of energy. As such, when I notice the freeze, it is when the screen is already dark and I am trying to wake it.

Sometimes, the screen goes from dark to gray. Other times, it fully lights up but shows the time from hours back. Sometimes, I can move the mouse (but no other response). Other times, I can do nothing. I've even left the iMac in that frozen state until the next day hoping that it'll come back alive. The monitor darkens again, but otherwise no better responsiveness.

My only recourse is to power cycle.

Additional info: there are no obstructions. And, I was unable to run any sort of HW diags even after putting in wired kbd+mouse. I tried D, Opt-D, no Internet, with Internet - nothing.

I did find the Snow Leopard disc and may try again later, but for now I am going to take a break.

The thought of a new iMac is coming back into my head again. I've had this for 5.5 years, and can use it as a back up desktop. I also have a 27" ACD attached to this that I can offer to one of my (or my wife's) Mac notebooks.

EVP