Fix the White Screen Issues on iMac

Mac that won't start up then it is an infuriating problem. If your Mac OS X simply doesn't start and it would get stuck on the white screen after the chime. This means that OS X can’t start because of problems with the system’s hardware or software. If your Mac fails to start up normally, there are a few things that you may try to troubleshoot the errors:-

Reset PRAM

Resetting of pram may fix your boot failure issues. Parameter random access memory known as pram stores your settings on need you can reset PRAM. For this:-

Turn off your Mac.

Now turn on your Mac and then immediately hold the option-command-p-r keys to restart your Mac again. When your Mac starts then un-hold the keys. http://mactechnical.kinja.com/how-to-fix-common-mac-problems-1774198819

Safe Boot Up

Safe boot checks the functionality of your Mac during start up process.

Simply shut down your PC while holding down the shift key until the logo passes. To get some response about what's happening on your Mac, you might choose to start up while holding down Shift+ Command,+ V key : That enters Verbose Mode, which spits out some feedback messages about what Safe Boot is actually trying to do as it goes. It can take a while but if your Mac starts up with safe boot then restart the system.

Otherwise, contact an expert support for Mac from a reliable third party support providing company and get your problems solved instantaneously.

Use terminal in single user mode

The steps given bell fix your problem. However if it doesn’t work then contacting a reliable Mac technical support is the right choice. Expert technicians help you in resolving your Mac white screen errors instantly.

The first 3 steps help you launch into the single user mode on your Mac.

·         Shut down your Mac.

·         Press the power button to start up your Mac.

·         Immediately Hold down Command-S for single-user mode.

·         On the terminal window Type fsck –fy and press return

·         Type mount –uw and press return

·         Type touch /private/var/db/.AppleSetupDone and press return

·         Type exit and press return

These steps will help you in fixing the white screen error.

Check the peripherals

 While using a Mac, check that all its peripheral cables are properly seated. Try reseating all the cables— to make sure they’re securely connected. If all other steps fail, try unplugging all peripherals one by one before trying to boot your Mac. http://mactechnicalsupport.jigsy.com/entries/general/resolve-and-diagnose-performance-issues-on-a-mac

 If your Mac starts back up without any issue, then you'll know that there is a problem with any of the peripherals. For this, you will need to shut your Mac back down, reconnect all the peripheral one by one, and then restart your Mac.