iMac black screen blinking

This morning my iMac 21" late 2012 started flashing a black screen, one a minute, and then it increased until the blinking/flashing was multiple times per minute. I've done the thing where you shut-down and pull the power cord out and then after a bit plug it back in (not a help), I've done a safe mode/boot and the blinking happened even MORE frequently, I created a new user account and it still blinked and flashed, I emptied Safari's web history, emptied the trash, did everything I could think of. I also ran Malwarebytes and no issues. Then by the afternoon, the whole screen went black but I could hear the HDD softly working in the display, pressed the esc key and it went beep (the screen was still black and the nothing would wake it up) so I did a CMD+Ctrl+power button and restarted it. A few minutes later the flashing started again.


Does anyone know what's going on? Any suggestions? I noticed that sometimes when the mouse moves over opened Finder that the flickering really speeds up. I made a video of it but can't see how to upload it.

iMac, macOS High Sierra (10.13.6)

Posted on Sep 15, 2018 3:15 PM

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5 replies

Sep 15, 2018 8:35 PM in response to MiskyBr

If you can get the computer to run long enough please do the following:


Please post an EtreCheck report of your system and we can look for any obvious issues. Please click the link, download and run the app and then post the complete report it produces as your reply to this message.


If you cannot get the computer to run long enough to post the report then please take the computer to your local Apple Store or Apple Authorized Service Provider for a diagnostic.

Sep 16, 2018 2:29 AM in response to rkaufmann87

Thank you. Here's the report.


EtreCheck version: 4.3.6 (4D041)

Report generated: 2018-09-16 10:16:52

Download EtreCheck from https://etrecheck.com

Runtime: 4:36

Performance: Good


Problem: Other problem

Description:

black screen flicker


Major Issues: None


Minor Issues:

These issues do not need immediate attention but they may indicate future problems.


Unsigned files- There are unsigned software file installed. They appear to be legitimate but should be reviewed.

32-bit Apps- This machine has 32-bits apps that may have problems in the future.


Hardware Information:

iMac (21.5-inch, Late 2012)

iMac Model: iMac13,1

1 2.7 GHz Intel Core i5 (i5-3330S) CPU: 4-core

8 GB RAM - Upgradeable

BANK 0/DIMM0 - 4 GB DDR3 1600 ok

BANK 1/DIMM0 - 4 GB DDR3 1600 ok


Video Information:

NVIDIA GeForce GT 640M - VRAM: 512 MB

iMac 1920 x 1080


Drives:

disk0 - APPLE HDD ST1000LM024 1.00 TB (Mechanical)

Internal SATA 3 Gigabit Serial ATA

disk0s1 - EFI (MS-DOS FAT32) [EFI] 210 MB

disk0s2 - Macintosh HD (Journaled HFS+) 999.35 GB

disk0s3 - Recovery HD (Journaled HFS+) [Recovery] 650 MB


disk1 - Western Digital My Passport 07B8 2.00 TB

External USB 5 Gbit/s

disk1s1 - EFI (MS-DOS FAT32) [EFI] 210 MB

disk1s2 - M*****************c (Journaled HFS+) 2.00 TB


Mounted Volumes:

disk0s2 - Macintosh HD 999.35 GB (859.48 GB free)

Journaled HFS+

Mount point: /


disk1s2 - M*****************c 2.00 TB (1.43 TB free)

Journaled HFS+

Mount point: /Volumes/M*****************c


Network:

Interface en0: Ethernet

One IPv4 address

2 IPv6 addresses

Interface en6: iPad

Interface en5: iPhone

Interface en1: Wi-Fi

802.11 a/b/g/n

One IPv4 address

2 IPv6 addresses

Interface en4: Bluetooth PAN

Interface bridge0: Thunderbolt Bridge

iCloud Quota: 37.91 GB available


System Software:

macOS High Sierra 10.13.6 (17G65)

Time since boot: Less than an hour

System Load: 1.61 (1 min ago) 1.64 (5 min ago) 0.93 (15 min ago)


Security:

SystemStatus
GatekeeperMac App Store and identified developers
System Integrity ProtectionEnabled


Unsigned Files:

Launchd: /Library/LaunchDaemons/com.microsoft.office.licensing.helper.plist

Executable: /Library/PrivilegedHelperTools/com.microsoft.office.licensing.helper

Details: Exact match found in the whitelist - probably OK


32-bit Applications:

28 32-bit apps


System Launch Agents:

[Not Loaded]8 Apple tasks
[Loaded]183 Apple tasks
[Running]102 Apple tasks
[Other]One Apple task


System Launch Daemons:

[Not Loaded]35 Apple tasks
[Loaded]192 Apple tasks
[Running]109 Apple tasks
[Other]One Apple task


Launch Agents:

[Loaded]com.microsoft.update.agent.plist (Microsoft Corporation - installed 2018-09-15)
[Loaded]com.google.keystone.agent.plist (Google, Inc. - installed 2018-07-18)
[Running]com.malwarebytes.mbam.frontend.agent.plist (Malwarebytes Corporation - installed 2018-08-06)


Launch Daemons:

[Running]com.malwarebytes.mbam.settings.daemon.plist (Malwarebytes Corporation - installed 2018-08-06)
[Loaded]com.microsoft.autoupdate.helper.plist (Microsoft Corporation - installed 2018-09-15)
[Running]com.malwarebytes.mbam.rtprotection.daemon.plist (Malwarebytes Corporation - installed 2018-08-06)
[Loaded]com.adobe.fpsaud.plist (Adobe Systems, Inc. - installed 2018-08-27)
[Loaded]com.microsoft.office.licensing.helper.plist (? 6d8cb30e - installed 2014-02-26)
[Loaded]com.google.keystone.daemon.plist (Google, Inc. - installed 2018-07-18)


User Launch Agents:

[Loaded]com.dropbox.DropboxMacUpdate.agent.plist (Dropbox, Inc. - installed 2018-08-22)


User Login Items:

iTunesHelper Application (Apple - installed 2018-07-18)

(/Applications/iTunes.app/Contents/MacOS/iTunesHelper.app)

Dropbox Application (Dropbox, Inc. - installed 2018-09-13)

(/Applications/Dropbox.app)


Internet Plug-ins:

FlashPlayer-10.6: (installed 2018-09-11)

QuickTime Plugin: (installed 2018-07-18)

Flash Player: (installed 2018-09-11)

SharePointBrowserPlugin: (installed 2017-09-19)


User Internet Plug-ins:

Picasa: (installed 2014-06-10)


Safari Extensions:

Adblock Plus.safariextz - Eyeo GmbH - https://adblockplus.org/(installed 2018-09-07)


3rd Party Preference Panes:

Flash Player (installed 2018-08-27)


Time Machine:

Skip System Files: No

Mobile backups: No

Auto backup: Yes

Volumes being backed up:

Macintosh HD: Disk size: 999.35 GB - Disk used: 139.86 GB

Destinations:

M*****************c [Local] (Last used)

Total size: 2.00 TB

Total number of backups: 215

Oldest backup: 2014-10-18 16:19:13

Last backup: 2018-09-16 09:25:03


Top Processes by CPU:

Process (count)Source% of CPULocation
mds_storesApple38
sandboxdApple12
mdworker (18)Apple8
mdsApple6
WindowServerApple5


Top Processes by Memory:

Process (count)SourceRAM usageLocation
kernel_taskApple906 MB
mdworker (18)Apple345 MB
mds_storesApple236 MB
Dropbox (3)Dropbox, Inc.202 MB
sandboxdApple61 MB


Top Processes by Network Use:

ProcessSourceInputOutputLocation
mDNSResponderApple262 KB76 KB
DropboxDropbox, Inc.135 KB101 KB
apsdApple8 KB16 KB
rapportdApple746 B778 B
netbiosdApple1 KB0 B


Top Processes by Energy Use:

Process (count)SourceEnergy (0-100)Location
mdworker (18)Apple8
WindowServerApple3
mds_storesApple0
Dropbox (3)Dropbox, Inc.0
SpotlightApple0


Virtual Memory Information:

Available RAM4.55 GB
Free RAM1.37 GB
Used RAM3.45 GB
Cached files3.19 GB
Swap Used0 B


Software Installs (past 30 days):

NameVersionInstall Date
Evernote7.42018-08-17
Gatekeeper Configuration Data1542018-09-07
Paint X Lite4.02018-09-10
Adobe Flash Player31.0.0.1082018-09-11
Microsoft AutoUpdate4.2.180812012018-09-15


Diagnostics Information (past 7 days):

2018-09-15 16:44:12 Safari.app Hang (2 times)

/Applications/Safari.app


2018-09-11 11:03:48 iTunes.app Crash

/Applications/iTunes.app

Performing @selector(terminate:) from sender JRNSMenuItem 0x6000002d82c0

abort() called

*** error for object 0x6000006201c0: Invalid pointer dequeued from free list



End of report

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iMac black screen blinking

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