I had the same problem with the optical drive in my MacBook from late 2006 after pouring milk into it late one night and did get a working install this way. Booting from USB is hit or miss with Macs (both PowerPC and Intel). I have made it work on an iBook Clamshell after running late versions of Tiger (but not after running earlier versions), but I have never been able to do it on an Intel Mac, except for a Mac OS X install disk from an USB optical drive (but not Ubuntu live dvds from the same drive).
This is a method to install Ubuntu on your MacBook using FireWire Disk mode. You will need another Mac with FireWire and a FireWire 400 cable. If the other Mac has FireWire 800, you will need a FireWire 400 to 800 cable. And you will need a disk to backup your Mac OS X install. (You also need this backup of Mac OS X to extract the firmware for your iSight webcam after the install.)
Maybe borrow another Mac from somebody if you don't have two. The other Mac must run Mac OS X 10.4.7 or later (PowerPC or Intel doesn't matter), since otherwise it will not be able to "see" the disk in the MacBook. (PowerPC Macs used APT, not GUID partition tables, so only after the Intel transition did the operating system get the ability to see GUID disks.)
What you basically do is install the Live DVD to one partition and install onto the rest of the disk from that partition. If you want to dual boot, you can restore your Mac OS X install to the partition we used for the Live DVD after installing Ubuntu on the other partition, but if you just want Ubuntu, then keep the other partion as a restore partition. Before partitioning, you will need to know if you want to dual boot or not to decide how large the partition you will use for the Live DVD should be. If you want to dual boot, you will have to make it as large as you want your later Mac OS X partition. If not, then it will just need to be large enough to fit the live .iso.
(I am not using the English localisation of neither Mac OS X nor Ubuntu, so the exact worthing of buttons and such might be slightly off in these instructions, but the gist of it is right.)
Here is how you do it:
- Backup your Mac OS X install to an external FireWire or USB drive. Use Carbon Copy Cloner from Bombich software (not Time Machine) if you want to dual boot. (We need an exact clone that we can restore to one of the partitions on your MacBook later, and since we can not use the Mac OS X Install disk to restore from a Time Machine backup since the optical drive doesn't work, we need an exact clone that we can restore with Disk tools from the other Mac.) NB: If you want to dual boot, make shure that your Backup does not take up more room than the size you will use for the Mac OS X partition later. (Delete all unnessecary stuff from your home folder if it is too large.)
- Download and install rEFInd and restart your MacBook twice (not one time, but two times) and shut it down again.
- On the other Mac, download Ubuntu live DVD 14.04 32 bit or 14.10 32 bit. After it is downloaded, click it and press Commando+I to get the "Get info" window. You need the information in this window later.
- Connect the FireWire cable to the other Mac and start your MacBook while holding down the T key. A FireWire symbol appears (looking like a flux capasitor) and on the other Mac, your hard drive appears in the Finder.
- Open Disk tools. (In the Tools folder inside the Program folder.)
- Select your MacBook's disk in the left panel and click the partition tab.
- Make a new partition by hitting the + on the lower left side. Drag the dividing line between the partitions upwards or downards untill it is the size you want. a) Single boot. If you want to just have Ubuntu on the MacBook, you will have to make it the size of the live iso file we downloaded earlier (look at the "Get info" window now). Add an extra gigabyte just to be shure (since sometimes a gigabyte is 1024 MB and sometimes it is 1000 MB). b) Dual boot. If you want to dual boot with Mac OS X, you will need to make your partition the size you want your Mac OS X partition to become later. Remember that this has to be bigger than the backup clone you made in 1 to work.
- Make the new partition MS-DOS (FAT32) formatted by writing a name in the field to the right of the partition layout and selecting MS-DOS and then "delete" (or "Partition". Can't remember exactly).
- Drag the .iso file from the Downloads folder into the left panel of Disk tools.
- Click the "restore" tab and drag the Ubuntu live iso into the "From..." field and the new partition you made in 7 into the "To..." field and click "Restore".
- Quit Disk Tools.
- Eject the two partitions from the MacBook in the finder by clicking the eject buttons on the right side of their names.
- Shut down your MacBook. (Hold down the power key untill the MacBook shuts down if it doesn't shut down immideatly.)
- Disconnect the FireWire cable.
- Restart your MacBook.
- Choose "Windows" when the rEFInd window shows up. It thinks it is windows because the disk is formatted FAT32.
- Choose install and go through the usual questions. (Tap to click is on by default, so be careful with your trackpad.) I usually choose not to update the installer, as it often seems to fail for me, but check the Fluendo restricted multimedia package, that is really nice to have. When you come to the place where you should choose where to install, choose "Manual setup" (or whatever it is called). DO NOT choose erase the whole disk and install (since the live iso you are running is also on the disk).
- Delete the other partition of the disk (the HFS+-formatted one) and make a Swap partition the same size as your RAM and another EXT4 partition that you make your root partition. Press "format" after setting the disk up as you like. (DO NOT repartition the FAT32 partition or do anything else with it at this time.)
- Install and when asked, choose to install grub on your root partition. (The EXT4-partition.)
- Dual boot only. Shut down your MacBook. Connect your Backup USB or FireWire disk to the other Mac. Reconnect your MacBook to the other Mac with the FireWire calbe and start the MacBook while holding down T. Choose "Ignore" when asked what to do with partitions Mac OS X can not read. Open Disk Tools (Apple menu->Recent items->Disk tools) and format the FAT32-partition to Mac OS X extended (choose the partition in the left panel (not the disk, only the partition) and use the delete tab to name it and make it Mac OS X Extended (Journaled). Go to the Restore tab. Drag your Backup disk to the "From..." field and the newly made Mac OS Extended (HFS+) disk into the "To..." field and press the "restore" button. Quit Disk Tools when it is finished restoring. Eject the other partitions and disks in the Finder and disconnect the FireWire cable. Restart your MacBook and at the rEFInd window you will now find Mac OS X and Linux.
Then you need to install firmware for the isight camera and fan control. (See my blog post for an explanation of how to do this.)