I'm hoping some of you gurus can give me a bit of direction here - I am not completely useless with Macs, but I am far from an expert so please forgive me if I am missing anything obvious. I have had this nasty problem when my 2011 MBP 15 starts up where I get 'thin red horizontal lines' on the start-up screen before it 'stalls' and just goes to the 'white screen'. A bit of background: 1. I had been having this problem for about 6 - 8 weeks prior to my latest drama 2. Initially I thought the laptop was toast (7 years old now), but after some googling it seemed that what I was experiencing was due to the AMD discrete video card being soldered with poor quality solder - or something to that effect, which caused big issues when the OS tried to 'use' that card instead of the integrated one. 3. My 'cowboy' solution was to hold down the Command / Option / P and R keys - which evidently resets some video RAM or something?? For some reason this seemed to work well (I would hold those keys down until the laptop had restarted for its 3rd time FWIW). 4. The above solution seemed to work well, although I was having this issue 2 - 3 times per week which was frustrating. A couple of times when I repeated the above process I got an error message saying that OS X was reinstalling due to errors - this was a bit concerning, but everything went fine after a short wait and none of my data was lost. 5. Unfortunately, when trying my Command / Option / P / R trick last week (and getting a message saying the OS was reinstalling) I got a scarier message saying the installation could not be completed, and asking me to check the installation log??? 6. It seems to now leave me with only 2 options, 1) to restart and try to continue the installation, or 2) to chose a different disk. (I may have had an older version of OS X on my second optibay drive at one point but not sure if it is still the case...not sure if this is relevant??). Option #1 leads me back to the same error/log message.....so it seems I am down to reinstalling from a different disk (assuming this means I can install another version of OS X from a memory stick???) 7. See the pic below for reference: So, I am out of my depth with the 'error log' and not really sure how to proceed. i) Is this the same (or related) issue as the original 'thin red lines' drama - or is this a new problem? ii) Can I download a DMG version of the latest OS onto a memory stick and simply reinstall the OS from there? iii) If I do the above, will it erase all my data? iv) Are there any clues in the Log regarding what is going on? Obviously I should just upgrade, but I don't have a budget for it right now and was hoping to get at least another 12 months out of it if possible. Any help or advice would be greatly appreciated. I am overseas at the moment and have some language issues combined with the fact that nobody really uses Macs here so I am kinda on my own! Big thanks in advance, --- Post Merged, Apr 2, 2018 --- *** I should also note that I have had a quick read through the "Force MBP 2011 to use Intel graphics card', but was a little intimidated by the steps involved, and consequently kept using the Command / Option / P / R method I mentioned.