Similar Questions

• My MacBook suddenly started running slow

  Reading this thread: my MacBook suddenly started running slow

  I followed the instructions of Linc Davis to post the following are produced by the Terminal application and using the command:

  syslog -k Sender kernel -k Message CReq 'Channel t|GPU D|I/O|find tok|n Cause: -' | tail | open -ef

  The following text has been updated with the door...

  Jan 29 06:47:19 core Mason-MacBook-Pro [0] : cause of previous stop:-60

  30 Jan 10:01: 18 localhost kernel [0] : cause of previous stop:-60

  30 Jan 10:19: 49 kernel Michael-MacBook-Pro [0] : SSanadnbdobxox: Sandboxmdmwdowrokrekre (r(: 38838) 5md woden) YY (d1e) n (f1) I i/oAns/ppClialceatindar.apop/Cns/onCatelnentdasrer d/Ap-daplticaat lef-irleea-dr-edaatark. () / Mapp/acO38S/CCona7) lteentn sd/MaacOrS /.

  30 Jan 10:19: 57 kernel Michael-MacBook-Pro [0] : SSaandndbobox: x: mmdwodrwkeorkrer ((385387)) dendeyny ((1) 1) fifillee-read-r-dateaad-d/Aatppal ination/Applionscati/oGansme /GaCentme er. Capenp/Contetern.ats/pMacpOS

  Jan 30 22:52:48 core Mason-MacBook-Pro [0] : nspace-Manager-unlock: found no token 11211

  3 Feb 07:16:39 localhost kernel [0] : cause of previous stop:-60

  There was several abnormal stoppages in the last days. A negative stop code may indicate a hardware problem. The precise meaning of the codes is not publicly documented.

  If you haven't already done so, you can try to reset the system management controller. Otherwise, or if the reset has no effect, see below.

  Do a 'genius' one appointment at an Apple Store, or select another authorized service provider. You may need to leave the machine there for several days.

  Back up the data on the internal disks before you turn on your computer to anyone. There are ways to back up a computer that is not fully functional - ask if you need advice.

  If privacy is a concern, delete the partitions of data with the ability to write zeros * (do it only if you have at least two backups complete, independent, and you know how to restore on a blank disc from any one of them.) Do not delete the recovery partition, if it is present.

  Keep your confidential data safe during the repair of the equipment

  Apple recommends that you remove permission to a device in the iTunes store before serving.

  * One SSD has no need to be set to zero.

• HP Officejet 4355 printer suddenly start very slow printing! HP technician advice needed!

  Hello
  My all-in-one HP Officejet 4355 printer start suddenly feel very very slow! I've had it for 4 years, and God never gave me any problems (maybe minor once, but never really made me mad), as I used it very often at home and at the office. I always buy the HP original ink cartridge (only once, when I wanted to see how works the charging - it's not) and now the last cartridge has been in the printer for a month or two, nothing unusual, and suddenly my printer starts to print very very slow, if normally it took 10-15 sec for a black and white page now it will take 10 to 15 minutes. Could someone suggest help?
  Please don't talk about the computer/Windows/USB settings, they all work very well. I unplugged the printer from the PC and don't "align the print cartridge. First step, the printed area, took 10 minutes, second step, part of scanning, does not pass. It says printer cannot allocate the alignment page...
  Moreover, I did look around for answers and found that some people say it's a fault of the ink cartridge. But I used this cartridge for a few months now, it's almost, but not yet finished, it was perfectly up to printing. Impressions during this issue come out OK, 7 out of 10.
  Anyone have any ideas? If I could attract professional assistance of technicians of HP, it would be perfect.
  
  Thank you.

  © RedStarLimitless ©

  Although they still ink cartridge may fail and give the results you see, where the printer made a bandage and wait 10-15 seconds for the next Strip. This is caused by the failure of one of your cartridges.  Remove each cartridge and clean the contacts on the cartridge and printer can solve the problem.

  I don't remember if the Officejet 4355 reserve mode supports, but try the following: remove the black print cartridge and print a test page.  The printer prints at a normal speed?  Is therefore the black cartridge was the issue and needs to be replaced.  If it isn't then, put the black back cartridge in and remove the color cartridge and the test page printed.  If the printer now prints speed the color cartridge is responsible and must be replaced.

• Computer suddenly starts running slow

  Hi all

  More computer problems - yay.

  I can boot my computer without problem. For about 2 minutes, it works perfectly - things open fast, close quickly, etc.

  Then all of a sudden, the whole system just slows down. All that I'm starting to take forever - the same computer hangs when I click on the start menu. Freezes completely, just for like 5, 10 seconds. But it happens every time, making it incredibly long to open anything (5 minutes for opening google chrome page.)

  I have a MSI motherboard with AMD drivers.

  I noticed that during the freeze, the computer disconnects from the internet (connected with an ethernet cable), raise above the symbol of the internet's yellow warning triangle.

  I start the computer in safe mode, fiddling around with a number of things when I got a warning window stating that I don't have an AMD graphics driver or that its does not work properly. This thread, I think it might be the drivers I installed using an MSI/AMD disc that came with the computer, so I installed them again using the disc, but no difference.

  System Restore does not work, I restored the closest point possible without success.

  Oh, I do not update windows, I had previous problems with windows after updates, so I cut them. This could it be? I'm not sure.

  Any help would be greatly appreciated!

  (1) try a "clean boot".

  How to perform a clean boot in Windows:
  (solve a problem by performing a clean boot in Windows Vista, Windows 7 or 8)
  http://support.Microsoft.com/kb/929135

  Perform a clean boot to determine if background programs are interfering with your game or other programs
  http://support.Microsoft.com/kb/331796

  One by one add back one application at a time in the boot list to check if a particular software application is the cause of the slow down.

  2) update your drivers from MSI web site

  Chances are the drivers to your MSI drive are older versions and have been updated:

  http://www.msi.com/product/MB/

  (3) scan your PC for viruses:

  Details of virus removal
  Download the free version of Malwarebytes, it will detect and remove most of the viruses.
  http://www.Malwarebytes.org/products/malwarebytes_free

  ESET Online Scanner:
  http://www.eset.com/us/online-scanner/
  ESET removal tool (Windows 7 only)
  Burn it to a CD or create a USB bootable thumb with her:
  http://KB.eset.com/esetkb/index?page=content&ID=SOLN3509

  BitDefender Online Scanner:
  http://www.BitDefender.com/scanner/online/free.html

  Kaspersky Rescue Disk:
  https://support.Kaspersky.com/viruses/RescueDisk
  Kaspersky Rescue Disk 10 is designed to scan and disinfect x 86 and computers compatible x 64
  who have been infected. The application should be used when the infection is so severe
  that it is impossible to disinfect the computer using anti-virus applications or malware removal utilities

  Kaspersky free Antivirus Scanning:
  http://www.Kaspersky.com/virus-scanner

  Norton Power Eraser
  http://security.Symantec.com/nbrt/NPE.asp?lcid=1033
  Note: Because the Norton Power Eraser uses aggressive methods to detect these threats,
  There is a risk that it can select some legitimate programs for removal.
  You should use this tool very carefully, and only after you have exhausted other options.

  Microsoft safety scanner
  http://www.Microsoft.com/security/scanner/en-us/default.aspx

  Also:
  Take a critical look at your current AV software, it is produced to date or old and obsolete.

  Unexplained computer behavior may be caused by deceptive software
  http://support.Microsoft.com/kb/827315

  J W Stuart: http://www.pagestart.com

  .

• Base HP EliteBook 8760w model: computer suddenly starts running slow

  I was playing a game when the FPS started becomes weak, and it is gradually degraded over time. I suddenly realized that my power cord was not connected to the computer, and he was running low on battery so I charged it. After loading, nothing has changed, my browser was slow, staggered games, youtube videos would be in audio delay, then speed up again, just acted really bad. The CPU usage was always about 100% and before all this, my computer has been perfectly fine, extremely fast and usually I would get 144 fps in the game, but now I get 2-12. I tried malwarebytes, safe mode, clean boot, reboot, let it rest overnight, with ca running but no battery, using optimized bios by default, ccleaner clean and ccleaner registry clean.

  I never encountered this problem before, is it a virus or did I burn/break something?

  @Regrettings

  Welcome to the Community Forum of HP.

  A few ideas

  Try a Hard Reset / forced:

  =================================================

  Hard Reset / forced

  • Close running of programs, the browsers and games

  Next

  • Create a Restore Point: create a restore - Win7 Point OR create a restore point Win8

  If you use a laptop

  • Close all your programs and shut down your computer
  • Unplug everything (little unifying for the keyboard / mouse external can stay)
  • Perform the forced reset for your laptop model
  • Start the computer and connect

  OTHERWISE, if you are using a desktop computer

  • Close all your programs and shut down your computer
  • Disconnect devices USB, speakers, other drives useless
  • Unplug the computer thirty seconds
  • Connect the power supply (plug in)
  • Reconnect the devices
  • Start / start the computer and log in

  Reminder: forced reset is a device reset.  The procedure do not destroy your files, or it destroys your Windows installation somehow.  Forced Reset "forces the system to erase and restore the software connections between the BIOS and hardware."

  =================================================

  More...

  • Try to reinstall your game.
  • Take a look at the overall performance from the point of view that the computer is probably not infected - it might be, but maybe it's a coincidence based on timing rather that on a computer running on battery - consider that the system may like to have low maintenance.

  Improving the performance of the system without adding memory (Windows 7)

  • Given the system beating on concern one of the programs that ordinarily would behave himself.  Take a look at the resource monitor - check what is running, how much resources each program uses, and whether these programs that are running are include as expected (not running Amok and steal all the resources).

  How to use Windows 7 resource monitor

  When you see a post that will help you,

  Who inspires you, gives a cool idea,

  Or you learn something new.

  Click the 'Thumbs Up' Kudos on this post.

  Click on accept as Solution when my answer provides a fix or a workaround!

• MacBook Pro keys stop and start working sudenly

  I have the Macbook Pro 13 "end 2011 with Osx El Capitan every time I turn on my mac, certain keys do not work as (A, F1, Backspace) I connect an external keyboard to type my password to the user, use like 3 minutes with external keyboard and laptop keys suddenly start working again, what is it possible already tried Reset the SMC and Landau."

  I also noticed that this happens whenever I have close the session of the user or shutdown my mac

• My MacBook Pro suddenly becomes very slow, accepting orders very slow how to check if the ram is working properly

  My MacBook Pro suddenly becomes very slow, accepting orders very slow how to check if the ram is working properly

  You can try this download.   Etrecheck.   https://etrecheck.com/#about

  Then publish the report as a reply in this thread.

  It will allow us to review your system without disclosing a private matter.

• I need help to connect my macbook pro to my TV high definition. I just installed the latest update for el capitan, and now all of a sudden not work there.  I use a hdmi cable that has worked for me before.  Any suggestions?

  I need help to connect my macbook pro to my TV high definition. I just installed the latest update for el capitan, and now all of a sudden not work there.  I use a hdmi cable that has worked for me before.  Any suggestions?

  OS X El Capitan: use your TV as a monitor

• DVD/CD RW optiarc dvd rw ad-7560 s ata device suddenly stopped working I get a "code 10 this device cannot start.

  My CD/DVD RW optiarc dvd rw ad-7560 s ata device suddenly stopped working I get a "code 10 this device cannot start.  I have uninstalled and still get this error.  When I put a CD in nothing happens.  It is not read.  Any suggestions?

  Hello

  Description of errors related to the 10 Code that generates the Device Manager in Windows on computers
  http://support.Microsoft.com/kb/943104/

  Step 1: Please do all the same underneath if you did some before as is often total
  a process that solves the problem.

  Try this - Panel - Device Manager - CD/DVD - double click on the device - driver tab.
  Click on update drivers (this will probably do nothing) - RIGHT click ON the drive - uninstall.
  RESTART this will refresh the default driver stack. Even if the reader does not appear to continue
  below.
  
  Then, work your way through these - don't forget the drive might be bad, could be a coward
  cable or slight corrosion on the contacts (usually for a laptop) and other issues.

  Your CD or DVD drive is missing or is not recognized by Windows or other programs
  http://support.microsoft.com/kb/314060 - a Mr Fixit

  Try this fix manually if the Fixit 314060 does not work
  http://www.pchell.com/hardware/cd_drive_error_code_39.shtml

  Your CD or DVD drive is missing or is not recognized by Windows or other programs-
  a Mr Fixit
  http://support.Microsoft.com/kb/982116

  The CD drive or the DVD drive does not work as expected on a computer that you upgraded to
  for Windows Vista
  http://support.Microsoft.com/kb/929461

  When you insert a CD or a DVD, Windows Vista may not recognize the disc
  http://support.Microsoft.com/kb/939052

  Your CD or DVD drive cannot read or write media - A Mr Fixit
  http://support.Microsoft.com/GP/cd_dvd_drive_problems

  CD/DVD drive does not appear in Windows Vista, or you receive this error in Windows
  Vista installation after booting from the DVD (AHCI)
  http://support.Microsoft.com/kb/952951
  Drive CD - R or CD - RW Drive is not recognized as a recordable device
  http://support.Microsoft.com/kb/316529/

  Hardware devices not detected or not working - A Mr Fixit
  http://support.Microsoft.com/GP/hardware_device_problems

  Another possibility is that the cables are loose. Remove ALL power, then make sure that the cables in both
  ends. Remove and replace, do not just tight. For laptops, you can often clean power and
  contacts data with a pencil eraser.

  Some DVD players do not use the Windows default drivers so check with the manufacturer of system and
  manufacturer of device to see if there is a firmware or drivers for your drive if necessary.

  ===============================

  Step 2: You have disc problems as the CD/DVD is actually 4 discs in 1 case (CD & DVD
  Burn and CD and DVD read). So it is not unusual for 1 or 2 operational so that other parts
  do it right.

  Did you follow the Troubleshooting Guide for the reader who still does not work? There are
  the entries in registry that the troubleshooter does not solve and those who "might" be the cause.

  Check with your Maker system and a device for the two possible firmware updates and
  the correct registry entries for your car.

  Here are the keys that I of course are those in question - for the subkeys of the CD/DVD drive
  as there will be other subkeys in these keys. Do not forget to ask specific keys involved as well as
  the parameters.

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\IDE

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Hardware Profiles\0001\System\CurrentControlSet\Enum\IDE

  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\ {4D36E965-E325-11CE-BFC1-08002BE10318}

  -----------------------------------------------------------------------

  You can probably find more info here and maybe even the exact registry for your CD/DVD settings
  drive from someone with the same model.

  Forums - a lot of expert real help
  http://Club.myce.com/

  CD/DVD units
  http://www.myce.com/storage/

  Use DevManView to locate the CD/DVD in the registry (be careful and do a prior Restore Point)
  nothing change) - find the DevManView device and then make a right click on it free in RegEdit.

  DevManView - free - an alternative to the standard Windows Device Manager, which displays all the
  devices and their properties in flat table, instead of the tree viewer
  http://www.NirSoft.NET/utils/device_manager_view.html

  I hope this helps.

  Rob Brown - Microsoft MVP<- profile="" -="" windows="" expert="" -="" consumer="" :="" bicycle="" -="" mark="" twain="" said="" it="">

• My blackBerry curve Smartphones suddenly started acting weird! does not work! Help!

  Hello everyone,

  I have a curve 8310 and 2 days ago, it started working too slowly... Sand clock little shows every time for like 10 secons, before even answering a call!

  In addition, even when I checked in my settings I want to save my text sent messages as long to have a record of my calls, IT does HAPPEN no! I can't see the messages sent from fourth today, I got a message saying "A lost call" and when I clicked to see, nothing happened! I could never find out who called me!

  Then the facebook application no longer works...

  These things never happened to me before... I have not installed anything new, and my 1 GB card has only 300 MB on the use...

  It is extremely slow...

  Please help me! IM in panic...

  Hi and welcome to the forums!

  Looks like you have some memory problems.

  Go to the OPTIONS - STATUS to write the total of the file and free file numbers.

  After that, pull the battery with the phone ON and leave it for a minute.

  replace and write the numbers again.

  Please send the back numbers.

  Thank you

  PS BREATHE!

• All of a sudden my computer started working very slowly.

  All of a sudden my computer started working very slowly. I did not load the new programs and nothing works in the background. What can I do to speed up performance. time to respond when I open a program should take place as quickly as it used to be.

  On Sunday, April 14, 2013 22:33:10 + 0000, Laptop1440 wrote:

  All of a sudden my computer started working very slowly. I did not load the new programs and nothing works in the background. What can I do to speed up performance. time to respond when I open a program should take place as quickly as it used to be.

  I can't be sure of what you said, but it looks like it is very
  probably that you are infected with malware.

  What anti-virus and anti-spyware programs do you run?

  Ken Blake

• How can Hi I get my cs5 to start working again? Suddenly, the serial number has become invalid

  How can Hi I get my cs5 to start working again? Suddenly, the serial number has become invalid

  If you purchased CS5, you should have the case (with serial number) and the original dvd or if you have purchased online, this serial number will be in your adobeID profile.

  If you have downloaded CS5 a few years back, you reinforced the installer?

  The serial number should work - contact adobe if you activation problems - it could be you have CS5 installed on more than two computers, the license only allows two facilities - if you are trying to install on a third computer, you will see a prompt to disable the software on other computers.

• My MacBook Pro is super slow

  Hey there

  I have a MacBook 13 inch 2013 Pro, who was running on the Mavericks until today. About two weeks ago, it started to slow down a lot, with the wheel of death, which appears after a few clicks. Since its launch, I have:

  -checked, CPU activity monitor was really low, whenever I checked (5% to 7% for the user the system)

  -Run disk utility, find some permissions and disk repair, finding nothing on the repair disk

  -run clean my Mac, there is about 5 GB of stuff that could have been deleted (but I didn't delete everything he found)

  -time machined to until the problem started, no change it

  -run a scan for virus ClamXav, he found a suspicious file, I deleted it

  -Update for Sierra, no change it

  No significant changes since doing this, the machine is still slow as *, and do all this took so loooong (the antivirus scan took three days. THREE DAYS!)

  Of course, I'm not in warranty anymore, I was when something similar happened last year and a part has been replaced (cannot tell the documentation all did...) Everything that you guys can think I should try before I go and pay for a repair?

  Back up your Mac if you have not already done so. Read https://www.apple.com/support/backup/to learn how to do this please. To learn how to use Time Machine read to use Time Machine to back up or restore your Mac. The reason for creating a backup, it's that the symptoms you describe pourrait be a sign of an imminent hard drive failure, data security is a major concern.

  Then, shut down your Mac and restart in 'Safe Mode '. To learn how to do it please read: try safe mode if your Mac does not start-up. Compare works your Mac in Mode for how safe it was.

  Then restart normally. If the same problem comes back, please read the section If a problem does not occur in safe mode for actions recommended to Apple.

  Finally, you can temporarily create a new user account and log into this account to determine if the problem also exists when connected to this account. To learn how to read How to test a question to another user on your Mac account. When you are finished troubleshooting, you can remove the temporary user account by following these instructions: macOS Sierra: remove a user or a group. Before you delete, confirm that you have not need of all the files that you have possibly set in this account.

  Let me know what you decide.

• IntelHD chips in MacBook Air start just less efficient?

  So I have a Core i5 MBA. 4 GB RAM, 128 GB SSD, and it is probably the strangest machine I've ever owned.

  Speakers just didn't work at all until yesterday when like magic, it started working, which - as a technician 16 - who actually me mystified but little matter... audio works now, so I do not take it any further.

  The problem, for that I'm here, it's that it's all around slow. Moving in the dock, the magnification is extremely agitated, scrolling is jerky, move the mouse happens to a framerate so poor that I'd swear I was on an old Compaq to 20 year.

  To tell the experience that I have-it feels like any Windows machine would be if it was freshly restored without the graphics drivers... except on a Windows machine, I can just track down the hardware of the device ID, find the graphics driver and everything is smooth again... but I'm not too well versed in the language of Macish. What I did the research, the graphics for my Intel HD3000 machine driver is bundled with updates so that it seems that I must rely on kext tools at the terminal to * maybe * trigger my graphic extension.

  None of this seems lead me anywhere I tried internet replicated several times, followed with every update available 10.7 has access to... and evidence of pages of search results at least 15 of things without success. Everything that happens seems also my brick machine, if I try to upgrade to El Capitan on the App Store. Tested the SSD to see if this might be the culprit, checked everything very well. I think that the integrated gfx would mean that if my gfx card was dead, I wouldn't be able to pass material Diagnostics (or even put on with success).

  Only thing I have not tried until now becomes the DMG for ElCapitan and create a bootable disc see if the last just quick MacOSX solves everything (that I'll do tonight).

  If that gets me nowhere... What could be the problem?

  IntelHD chips in MacBook Air start just less efficient?

  N °

• resolution 2560 x 1440 has suddenly stopped working. 1080 p now the max option available

  I have 2010 macbook pro (el capitan) and ASUS H257HU monitor that supports the resolution 2560 x 1440. Until yesterday, I was able to get the full resolution, but suddenly it has stopped working and the max resolution I could get was 1080 p.

  I tried to reset the smc and NVRAM, but that did not help.

  In safe mode, I followed the suggestion of apple and was able to get resolution of 2560. But it reboots the machine back to 1080 p. Hold down the option key and clicking on the option scale does not display any resolution above 1080 p.

  I've tried searching and following some recommendations, but no permits.

  Restart the computer and enter views sometimes give 2560 option, but clicking on it makes the screen turns blue and then it always comes back to 1080 p, with no options available in the dialog on the scale. The System Preferences dialog box hangs for a few seconds.

  Someone at - he fell on the same issue and found a solution. I don't know why he suddenly stops working, while still being able to work in safe mode but not in normal condition. I tried to remove the profiles as well.

  With bootcamp (win 7), the display works fine with 2560 x 1440.

  The connector I use is screen Mini DisplayPort.

  All proposals/solutions will be very well received.

  Hello there, moths.

  It seems that you are having problems to select the resolution you want on your external display from ASUS. Great job with the troubleshooting, you've done so far. The following Knowledge Base article offers strong information to look over and review, as well as links to some additional troubleshooting content:

  Get help with graphical problems on external displays connected to your Mac.

  Before you start

  You can solve many problems of display by updating the software on your Apple devices, cables and adapters. If you see an image on your screen, look for the software updates using the Mac App Store:

  1. Connect your external display and Apple video cables or cards that you use with it.
  2. In the Apple menu, click App Store.
  3. Click updates in the window of the App Store.
  4. Install OS X updates or firmware are listed.

  If you use a display, hub, extenders or adapter not made by Apple, check with the manufacturer for updates that might be available.

  If you try to connect a screen 4 K or Ultra HD TV with your Mac, make sure that your computer meets the requirements for the use of these external displays.

  If your firmware and software are up to date, or if you don't see the image on your screen, try the steps below for your specific problem.

  {...}

  Check the connections

  Check the connections on your Mac and external screens:

  • If you use an Apple laptop computer, try to connect the AC adapter.
  • Make sure that the power cable from the external display is connected correctly and that your display is enabled.
  • If you are using a Mac Pro (end of 2013), make sure that your screens are plugged into the right ports.
  • If you use a hub of display, Cabinet or "KVM", try to connect the video cable from your screen directly to your Mac instead.
  • Unplug the video cable where it plugs into your Mac, then reconnect to reinsert the connection.
  • If you are using a video card, unplug the video adapter on your Mac, then reconnect to reinsert the connection.
  • If you use multiple video cards to connect your screen (the cards are "chained"), testing connection of the screen by using a single adapter if possible. Some video cards may not be linked together. For example, a mini DisplayPort to DVI adapter may not be connected to an adapter DVI to HDMI.
  • If your screen has more than one video connection, see if you are using another connection on the display works. If possible, check if you use a different view or a different adapter works.
  • Try using another cable that you know to be in working condition. Check with the manufacturer of the screen to make sure that you use the cable they recommend.

  Detect your display

  If you use an external monitor, sleep and wake your Mac to check for connected screens:

  1. Press the power button on your computer to standby, or choose the Apple menu > sleep.
  2. Wait a few moments, and then press a key on your keyboard or click your mouse or trackpad to wake up your Mac.

  If you use more than one screen, and you can see the image on one of the screens, you can also use the preferences monitors to check the connected screens.
  

  Adjust video settings

  If there is no image on the screen, try adjusting the brightness or contrast of the screen. If there is still no picture or image appears torn, or scrambled, try selecting a different video resolution in system preferences. Adjust brightness

  • If you use an Apple Display Monitor, press the key to increase brightness your Apple keyboard. To adjust the brightness of a secondary screen, press Control + F2.
  • If you use a view that is not made by Apple, see the documentation that came with your monitor to see if it includes built-in controls to adjust the brightness or contrast.

  Change your display resolution

  1. In the Apple menu, choose System Preferences.
  2. Click the display icon.
  3. Click default for display. If you see more than one resolution listed, choose a resolution and refresh rate. If the display turns off when you change resolutions, press the ESC key to cancel the change.
     

  If you can not change the resolution of your screen because you see no image, restart your Mac in safe mode to reset the default display resolution.

  If booting safe mode doesn't resolve the problem, reset your Mac NVRAM and SMC to reset the video ports on your Mac to their default values.

  Search for software third display

  If your monitor only works when your Mac is started in safe mode, and related to the software display is installed, check with the developer of the software for updates, or try to uninstall temporarily.

  {...}

  Get more help

  If you have tried these steps and your screen still does not work, contact the Apple support for more help.

  Thank you for being a part of the communities of Apple Support.

  See you soon.