Answer to: MacBook dead, not charging, new chargerHow long does it take for the light on the charger to light up? This is very important. If the light doesn't turn on immediately then this suggests there is a failure with the one-wire circuit or other power rails. It's a critical circuit for current sensing and allows the device to charge when the charger is connected. On top of this, the one-wire circuit is also powered by G3H. If G3H is missing, then the device will not boot. If it still isn't working now, it sounds to me like some important power rails aren't being created. It's possible your battery could have caused a failure along G3H, depending on how long you have had it. It's hard to say without actually looking at it and diagnosing it under a microscope. Even without a battery, the Macbook should still turn on when plugged in to the charger. The fact that it doesn't tells me G3H is shot. Of course, it could also be any number of other things. There's no way to know for sure without diagnosing it on a board-level.
Answer to: Power supply wiring for AudiostationYou can very easily identify which of the wires are for ground at the very least. Strip each wire to expose the copper, then, using a multimeter, set it to continuity mode and touch one probe to the black wire and another to a screw hole or metal shielding on the board for the station. If you hear a beep, then the black wire is ground. This is a very common configuration for wiring. You can possibly figure out if the red wire is for VCC (where the hot line from the adapter will go) by toning out the red wire from the station to regions of the board. If you can take the unit apart you should be able to very easily identify where each of those wires go to on the board. It's really something where you'll just kind of have to read the board to figure it out. I doubt everything in there runs off of 13V, that 13V is most likely boosted or pulled down to a lower voltage at some point on the board to power logic-level circuitry. If there's nothing glaringly obvious to tell you that the red wire is for VCC (like a lab...
Answer to: Will rubbing alcohol damage my LCD?You really don't want to use rubbing alcohol. It's not quite the same as isopropyl alcohol. While it is mostly comprised of isopropyl alcohol, bottles labeled as rubbing alcohol commonly contain other ingredients such as dyes and perfume oils to give it a less intense and more diluted smell compared to 91% or 99% isopropyl. For what it's worth I highly advise not attempting a glass-only repair on your phone unless you have prior experience with the processes involved. Even individuals who have been doing display refurbishing for years have difficulty with the Edge models.