Answer to: Why won't my screen turn on but my cd drive will?Sorry your having trouble. Here's what I'd do. 1. Plug in an external monitor. ReStart computer. If you see something on external then you have an issue with your macbook internal display. If nothing comes up on external then ... 2. Do a PRAM reset by holding down (Command+Shift+P+R) and keep holding them down while you press the power button. Hold down until you here the second startup chime then release. 3. Perform an SMC reset. Just google SMC reset with the model number of your Macbook and it's pretty straight forward 4. Hold down the "option" key when starting up. If you see a recovery screen then you are a little closer. I hope this helps. Not knowing exactly what is happening is difficult to diagnose but this should get you started.
Answer to: Not showing home screenIt means that there is one of two things happening. 1. There is no physical HardDrive inside the computer 2. There is a HardDive but it is corrupted and needs to be replaced. I would just pop open the computer and look for a hard drive. In either situation it would seem you'd need to purchase a Hard Drive. Hope this helps.
Answer to: Pentalobe Screws and Apple WatchPentalobe Driver sizes: Who knows what is the exact name and tooling to remove the pentalobe screws to change the leather watch strap? Is it a TX4? The exact size for the Apple Watch Band is PL2 0.9 mm It's hard to find. Look for wiha pentalobe 5-point driver set Pentalobe sizes P sizes TS sizes PL sizes Dimension Usage P1 TS0 Unknown P2 TS1 PL1 0.8 mm iPhone 4 (Late), 4S, 5, 5C, 5S, 6, 6 Plus, 6S, 6S Plus P3 TS2 Unknown PL2 0.9 mm Apple Watch Band P4 TS3 Unknown PL3 1.1 mm P5 TS4 PL4 1.2 mm MacBook Air and MacBook Pro with Retina Display P6 TS5 PL5 1.5 mm MacBook Pro (2009) Battery - 15” only. Also known as Apple specialty tool 922-9101 PL6 1.6 mm The iFixit set only includes P2, P5 and P6. Pentalobe Wiki