Previously I had not completely disabled the NVIDIA card so the
machine ran very hot and noisy for a macbook. It is now silent and
The other good tip was upgrading the wifi, the whole machine is now
The OSX side of the dual boot is still completely fritzed. I guess I
will take it up to Computer Assistance but the urgency has gone away.
On 13 May 2016 at 15:50, Tim Pizey <firstname.lastname@example.org> wrote: > Hi,
> Given that I am able to get the system running using a 2015 USB what
> say I just reinstall?
> On 9 May 2016 at 23:33, Tim Pizey <email@example.com> wrote:
>> Hi all,
>> This is a bit long and ponderous, with rather a lot of mac specific
>> questions, for which I beg indulgence.
>> I have had a 2011 macbook pro, modded by original purchaser to 16G and
>> a 250G SSD since 2012.
>> I dual booted it to ubuntu using UEFI (refind), which did not go very
>> smoothly, I am not using the full power of the radeon graphics card,
>> it has run rather hot and will not do html5 canvas cleverness.
>> I have had occasional issues with the wifi dropping out, but
>> increasingly, recently, I have had problems with gmail on chrome:
>> black blocks leaking between chrome sessions and other oddities.
>> I have been able to fix by turning off and on again, letting the
>> machine cool down and similar.
>> Last night it gave up and will no longer boot into linux or osx.
>> It starts fine, but on linux the screen goes black and on OSX white.
>> This is caused I suspect by the additional graphics card having died.
>> I am able to boot from an old (2015) Ubuntu USB, the system runs hot
>> so I think that the graphics card is in use.
>> I have quite a few choices:
>> 1. Disable the additional graphics card and use the onboard one.
>> If I can get to grub I could follow
>> https://help.ubuntu.com/community/UEFIBooting >>
>> outb 0x728 1 # Switch select
>> outb 0x710 2 # Switch display
>> outb 0x740 2 # Switch DDC
>> outb 0x750 0 # Power down discrete graphics
>> however I cannot get to grub. Pressing F2 from the UEFI menu does not
>> give me a grub menu.
>> Booting to single user mode does not get me a non-X shell and displays
>> a black screen.
>> 2. This seems to be a known problem, with a possible no charge, known
>> fix from apple.
>> 3. I have a spare, dead, 13 inch mac of the same vintage which I could
>> take a graphics card from (would this work?)
>> 4. I can get a working system and can edit the disks from the USB
>> Ubuntu, but I cannot figure out where to add the grub string or how
>> to rebuild grub from a usb based instance.
>> 5. Transfer the SSD to a Latitude E6500 that I am writing this on.
>> Any comments very welcome.
>> Thanks in advance
>> Tim Pizey - http://tim.pizey.uk/ >
> Tim Pizey