iMac mid 2010 27" is screaming at me

I have an iMac 27" mid 2010. When it is being used to watch You Tube videos it will make a supersonic screaming sound and must be physically turned off with the power button. The computer just stops working. Could I be looking at a failing hard drive or fan? Any ideas will be appreciated.
Dennis PillowOwner G-Tech Consulting LLCAsked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Paul SauvéRetiredCommented:
does this occur event with the speakers off?

if the sound is coming through the speakers, then it is possible a problem the sound card

supersonic - when an object goes faster that the speed of sound...    ;-)
Dennis PillowOwner G-Tech Consulting LLCAuthor Commented:
I have seen it do this with just normal use, not using the sound. The sound does not seem to come from the speakers and when this happens there is no control for anything.

Note: Maybe I should have used the analogy of a sound like a 600 cycle generator on the flight line in the winter in Alaska....That is loud :-)
Aaron TomoskyDirector of Solutions ConsultingCommented:
Sounds like the fan. Cheap enough part unless it's the fan on the Graphics card. A store will usually charge $200 just to open an iMac and replace it. There are suction cup kits to pull the glass off yourself but be careful if you do.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Acronis Global Cyber Summit 2019 in Miami

The Acronis Global Cyber Summit 2019 will be held at the Fontainebleau Miami Beach Resort on October 13–16, 2019, and it promises to be the must-attend event for IT infrastructure managers, CIOs, service providers, value-added resellers, ISVs, and developers.

Learn more
Dennis PillowOwner G-Tech Consulting LLCAuthor Commented:
Thank you for the heads up. I will try the solution.
Aaron TomoskyDirector of Solutions ConsultingCommented:
Easy test:
Get a can of compressed air, remove the memory cover  (the vent at the bottom center) then when it makes the noise blow some bursts of air at the noise, probably straight up. If the noise changes with the air, it's absolutely the fan.
Dennis PillowOwner G-Tech Consulting LLCAuthor Commented:
Will Do!
David AndersTechnician Commented:
Resetting the SMC is often suggested as a first step.
https://support.apple.com/en-us/HT201295

Google "imac fans loud"
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Mac OS X

From novice to tech pro — start learning today.