MacBook Pro boots with green apple logo, then gets a gray screen freeze

I have had my 2010 Mac Pro fail with a Green apple logo, which I took to a 'bloke' who fixed it - for a few months. I added a SSHD, which may have put too much strain on the graphics card - which i think is used for HD as well ! It failed again after a few more months. Repairs repeated. It is now failing with a RED apple. Looks to me like a hardware fault. the 'bloke' said it needed soldering - which I doubt frankly. It keeps going down. This time before it died, the display broke up in to horizontally offset comb like alternate lines which darted around the screen a few seconds before settling down and being fine for an hour or so. When I woke it from sleep, the screen stayed black. A forced reboot brought up the Red Apple - alternate lines missing totally. Previously the Green apple error also had missing alternate lines.

Any ideas? I can't keep going back to that chap. He 'fixed' it three times for the price of one. I fear the Genius bar will be rather costly.

Gray, Blue or White screen at boot, w/spinner/progress bar

..Step by Step to fix your Mac

Take each of these steps that you haven't already tried. Stop when the problem is resolved.

b. If you have access to a working Mac, and both it and the non-working Mac have FireWire or Thunderbolt ports, boot the non-working Mac in target disk mode. Use the working Mac to copy the data to another drive. This technique won't work with USB, Ethernet, Wi-Fi, or Bluetooth.

c. If the internal drive of the non-working Mac is user-replaceable, remove it and mount it in an external enclosure or drive dock. Use another Mac to copy the data.

Step 2

Press and hold the power button until the power shuts off. Disconnect all wired peripherals except those needed to boot, and remove all aftermarket expansion cards. Use a different keyboard and/or mouse, if those devices are wired. If you can boot now, one of the devices you disconnected, or a combination of them, is causing the problem. Finding out which one is a process of elimination.

If you've booted from an external storage device, make sure that your internal boot volume is selected in the Startup Disk pane of System Preferences.

Step 3

Boot in safe mode. Note: If FileVault is enabled, or if a firmware password is set, or if the boot volume is a software RAID, you can’t do this. Post for further instructions.

Safe mode is much slower to boot and run than normal, and some things won’t work at all, including wireless networking on certain Macs.

The login screen appears even if you usually log in automatically. You must know your login password in order to log in. If you’ve forgotten the password, you will need to reset it before you begin.

When you boot in safe mode, it's normal to see a dark gray progress bar on a light gray background. If the progress bar gets stuck for more than a few minutes, or if the system shuts down automatically while the progress bar is displayed, your boot volume is damaged and the drive is probably malfunctioning. In that case, go to step 5.

If you can boot and log in now, empty the Trash, and then open the Finder Info window on your boot volume ("Macintosh HD," unless you gave it a different name.) Check that you have at least 9 GB of available space, as shown in the window. If you don't, copy as many files as necessary to another volume (not another folder on the same volume) and delete the originals. Deletion isn't complete until you empty the Trash again. Do this until the available space is more than 9 GB. Then reboot as usual (i.e., not in safe mode.)

If the boot process hangs again, the problem is likely caused by a third-party system modification that you installed. Post for further instructions.

Step 4

Sometimes a boot failure can be resolved by resetting the NVRAM.

Step 5

Launch Disk Utility in Recovery mode (see Step 1.) Select your startup volume, then run Repair Disk. If any problems are found, repeat until clear. If Disk Utility reports that the volume can't be repaired, the drive has malfunctioned and should be replaced. You might choose to tolerate one such malfunction in the life of the drive. In that case, erase the volume and restore from a backup. If the same thing ever happens again, replace the drive immediately.

This is one of the rare situations in which you should also run Repair Permissions, ignoring the false warnings it may produce. Look for the line "Permissions repair complete" at the end of the output. Then reboot as usual.

Step 6

Reinstall the OS. If your Mac was upgraded from an older version of OS X, you’ll need the Apple ID and password you used to upgrade.

Step 7

Repeat step 6, but this time erase the boot volume in Disk Utility before installing. The system should automatically reboot into the Setup Assistant. Follow the prompts to transfer your data from a backup.

Step 8

A dead logic-board battery in a Mac Pro can cause a gray screen at boot. Typically the boot failure will be preceded by loss of the startup disk and system clock settings. See the user manual for replacement instructions.

Step 9

If you get this far, you're probably dealing with a hardware fault. Make a "Genius" appointment at an Apple Store to have the machine tested.

My late 2011 macbook with 10.11.2 crashed and I got a Green apple at startup, then it would reboot by itself , and again, and again, tried step #4 resetting the NVRAM. and it work for me, It took time to boot the first time but its working like before, thank you !! Linc Davis