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cleanneon98

macrumors newbie
Original poster
Nov 29, 2019
3
0
I'm at my wit's end here, have a Late 2015 iMac Retina, running OS Catalina all up to date. When I put it into sleep mode, the screen turns bright blue after 5-10 minutes and stays that way until the unit is woken up. If I dim the display brightness, the brightness of the blue screen does not change, but once it wakes up it goes down to the normal brightness level. It does this randomly, sometimes yes, sometimes no. I've tried restarting, unplugging, etc. I also removed all of the startup programs and the issue went away and then came back a few days later (there are still no items in the start up area).

The function of the display is not affected, and the computer still works fine, but its really annoying, and I'm sure its not good for the display to be on at that brightness all the time, in a solid blue color. There are no error messages on the screen, no prompts to do anything. The few programs I use (Zwift, TrainerRoad) don't seem to be causing this because other users have not reported these issues.

Oddly I cannot find anything relating to this issue online, very few other people have had this problem it seems. Anyone have any advice? I really don't want to have to shut this thing down and start it back up every time I have to use it but that's what I've resorted to otherwise my room has a bright blue glow when the unit is in sleep mode. Not sure if there's a virus scan or something I can run, or if this is a common issue I'm not aware of. Please help!

mac-blue-screen-of-death_thumb800.jpg
 

cleanneon98

macrumors newbie
Original poster
Nov 29, 2019
3
0
Suggest a shut down, remove all peripherals, unplug and then a reboot. Option 2 is reset the PRAM. Do you have a second monitor attached? If no joy have a read of this from Macworld:-


https://www.macworld.co.uk/how-to/mac-software/fix-blue-screen-mac-3673541/
No external display, and the only peripherals I have are some empty USB cords and an ANT+ Dongle for my smart trainer, but those have been plugged in constantly for years. Maybe there's an issue with the new OS with them. According to that guide I've done everything up to step 11, so step 12 is next with the safe mode launch and running disk utility, is that the PRAM reset or something else?
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Also, the computer boots up and wakes up and functions as normal, there's no issues with firing it up if its shut down, its just when its in sleep mode it turns blue. I think if I leave it on screen saver mode and then it shuts off the display, it won't do the blue screen either, but will play with the above tonight
 
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Snorkledorf

macrumors newbie
Oct 18, 2011
7
0
Kansai, Japan
Other people are seeing this, including a family member of mine who upgraded to Catalina. For the moment she's shutting her iMac down overnight, but is looking for solutions. She's poked around on the Japanese web and found a number of other people who are seeing this.

An Apple support thread here talks about it, though nothing has been resolved yet, other than suggesting that everybody send feedback to https://www.apple.com/feedback/.
 
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Bbri

macrumors newbie
Apr 16, 2020
1
0
I have a fairly new iMac, 2017, updated to latest Catalina OS. Getting the exact same blue screen issue ever since I updated to Catalina. Also exhibits the normal screensaver progression to sleep as described by cleanneon98. I've been mostly shutting down instead of putting to sleep.
 
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ProTruckDriver

macrumors 6502
Jul 28, 2016
254
322
Virginia
I guess Apple hasn't fixed this problem yet. I just got my first "Blue Screen" in Sleep Mode over night. Put the iMac in Sleep Mode last night, looked at the iMac this morning with a Blue Screen. I've updated to Catalina about 3 months after release date and never had a problem until now. We'll see if it keeps on Blue Screening in Sleep Mode for the next few nights.
 
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ProTruckDriver

macrumors 6502
Jul 28, 2016
254
322
Virginia
Other people are seeing this, including a family member of mine who upgraded to Catalina. For the moment she's shutting her iMac down overnight, but is looking for solutions. She's poked around on the Japanese web and found a number of other people who are seeing this.

An Apple support thread here talks about it, though nothing has been resolved yet, other than suggesting that everybody send feedback to https://www.apple.com/feedback/.
The Blue Screen appeared again this morning. :( Sending in feed back with the link above.
 
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ProTruckDriver

macrumors 6502
Jul 28, 2016
254
322
Virginia
Does anyone know if Big Sur is doing this Blue Screen while in Sleep Mode? I have been doing some research on this problem and I seen that Mojave has done it a few times also. I didn't see anything about Big Sur. I really don't want to upgrade to Big Sur because of what it looks like, an iPad. But I might have too upgrade if Big Sur is not doing it.
 
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armindillo

macrumors newbie
May 3, 2021
1
0
I have this sleep problem whenever my USB trackball is plugged in.
To get the iMac to sleep I need to unplug the trackball.
Before Catalina this problem did not exist on this computer.
 
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