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monitor brightness keeps going to max under Catalina

Since upgrading to Catalina this week, the brightness level for the monitor keeps going from the ~50% level setting to full brightness either whenever I turn on computer or it has been in more than a momentary sleep mode.


See attachments for what my settings have been set at.



iMac 21.5", macOS 10.15

Posted on Jan 15, 2020 11:11 AM

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Posted on Jan 17, 2020 3:38 PM

I am aware the iMac is older and Catalina made it even slower.


As far as the startup items, half are due to Adobe (as I have the Creative suite). I do not use Google, so their items are of unknown arrival.


I will live with manually adjusting brightness until I get a new machine.


Even though the problem is not resolved, I thank you for your input

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Jan 17, 2020 3:38 PM in response to rkaufmann87

I am aware the iMac is older and Catalina made it even slower.


As far as the startup items, half are due to Adobe (as I have the Creative suite). I do not use Google, so their items are of unknown arrival.


I will live with manually adjusting brightness until I get a new machine.


Even though the problem is not resolved, I thank you for your input

Jan 16, 2020 10:56 AM in response to Derryl S

Okay, please do the following:


Please navigate to the Mac App Store and download the free version of EtreCheck OR please click www.EtreCheck.com where you will find the app. Once you downloaded the free app and created the report please post it as your reply to this message. In order to post it, please use the following link for more detailed instructions on how to correctly include the results: 

 

https://discussions.apple.com/docs/DOC-250000211


We can then look for obvious issues that may be causing your problem.



Jan 17, 2020 1:28 PM in response to rkaufmann87

I ran etrecheck and it ran almost 12 hours and never finished. Rebooted and I could not get the Mac to finish booting. PRAM reset, Safe Mode, and then multiple restarts finally got the system going. Called Apple and did some resets.

Just ran etrecheck and it took less than 15 minutes to complete. That report is included. Could not attach the report file.


Even with Apple resets, brightness is still going back to 100% on booting and prolonged sleep.


Jan 17, 2020 3:18 PM in response to Derryl S

To be perfectly honest I am a little surprised it runs at all. You have an entry level iMac with 8GB of un-upgradeable RAM and a glaciallly slow 5400 RPM HD. These machines were intended to send e-mail and surf the net, you are doing quite more than that.


You also have some pretty ancient software on it and what appears to be a LOT of startup items. Considering there is so much stuff on the computer and much of it I'm sure you have not used in years I would do an erase and install and start over. I would then just restore your data files and then manually re-install the apps you want to continue with. Also, when you do this, do no add very much to your login items. Personally I only have 1 log in app, compared to your close to 10.

monitor brightness keeps going to max under Catalina

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