A SOLUTION of sorts (so far, so good for a week now)
For two months my 15" mbp (late 2011, 2.4 Ghz Intel Core i7, 8GB ram, AMD Radeon HD 6770M, Intel HD Graphics 3000, latest Mavericks OS) has been crashing and burning with the ubiquitous GPU problem.
The only way to boot was multiple times via Internet Recovery and SUM (to clean up permissions, etc.) Cannot boot from USB to recover (always blue screen), the DVD drive died a long time ago and no second mac to link to.
Enough was enough, so:
1. I backed up my data and completely erased the drive with Internet Recovery Disk Utility (Fastest).
2. Then using Internet Recovery (command R) I installed Lion (which was the only install option given).
3. Installed gfxCardStatus v.2.2.1
http://www.downloadcrew.com/article/27732-gfxcardstatus
http://www.pcadvisor.co.uk/downloads/3328418/gfxcardstatus-221/
4. Checkbox gfxCardStatus to 'Integrated Only' and uncheck Preference 'Use power source-based switching'.
5. Then choose System Preferences > Energy Saver > Better Battery Life.
6. Install smcFanControl > Preferences > 4000rpm default.
http://www.eidac.de/smcfancontrol/smcfancontrol_2_4.zip
7. (Optional) Install Photoshop > Preferences > Performance > Graphics Processor Setting > Uncheck "Use Graphics Processor".
Reinstall your favourite apps and use your backup to get your browser plug-ins, contacts etc.
When you back up, also back up (iCloud?) as separate files your contacts , bookmarks, little snitch settings (if you use), etc. which makes it easier to find them when reinstalling.
Caveat: the only time it has crashed is when I put it to sleep without the cable (on battery) and woke up to a black screen with the disk still spinning, so I though bx11oxs, but after a PRAM reset (Command, option P,R (hold twice until you hear the loud boot up tone)) and two restarts it came back to life. So when putting to sleep probably best to keep the mains cable plugged in. (I do put it to sleep for 30 minutes when taking to work with no problem).
I haven't risked any graphics intensive software like video editing or 3D games but I can surf, use YouTube, VLC, DVD Player, Photoshop (but no silly business with the filters), Illustrator, Acrobat, iWorks, MS Office, uTorrent, etc.
My mac is cool to the touch (46˚C), faster and I can't hear any spinning fans, and I've rebooted with no problems all week, it's almost like having my old friend back.
Eventually I will probably get a reball, but as I'm in Thailand my options are limited (perchance, does anyone know a good lead (as in zeppelin) reballer in Thailand?). If I send to the UK or US I will probably have to pay local customs a lot of 'tea money' when it's returned. I'm loathe to fork out my hard earned wonga on a 'new' logic board which by all accounts will shuffle off within months.
I have a feeling Mavericks has something to do with it, maybe more processor hungry, I don't know I'm not an expert, Lion just seems a lot more stable.
Also I used to work for large design houses and corporate consultants who had offices full of macs but I've not seen one of them shouting about it on these forums, just individuals, why?
Give it time and the newer models will start to show the same problems.
So, I hope some of you can find this solution useful - it took a lot of messing about and research on the interwebs and a bit of luck to work this out.
Here are some useful SUM scripts (my thanks to various sources) - copy and paste:
1. Always do these two first .
fsck -fy / (do this as many times until it says no modifications)
mount -uw /
2. To repair permissions
/usr/libexec/repair_packages --repair --standard-pkgs
3. Disk repair (fixing invalid node structure)
ls -1 /dev/disk* (to find which is your startup disk)
fsck_hfs -rf /dev/disk0s2 (hfs for mac formatted and 0s2 for my particular HD)
4. Use this to clean your mac when it is really fxxxed up)
fsck_hfs -y -Rc -d /dev/disk0s2
5. Turn on / off wifi
networksetup -setairportpower airport on
networksetup -setairportpower airport off
I tried using Applejack but it didn't do much, the above scripts are a lot more useful.
Chock dee krap