"battery shuts down on start up"に関する回答I’m assuming it’s a Macbook of some kind since you mention it’s got a battery… year and model would be helpful. Other than that, I think you said your MacBook has a couple of problems: (1) Makes 3 beeping sounds when you start it (2) Does not fully start up and shuts down when the progress bar is around 75%, even after a PRAM reset (3) Only starts with power adapter plugged in, but will run on battery alone after it has started For #1 - either bad or loose RAM. Try reseating or replacing it. I would unplug the battery before doing this. For #2 - could be a bad drive or OSX errors - what version are you running? If you have a newer version, get into recovery mode (hold Command + R keys after starting) and try Disk Utility to fix any errors. For older OSX, you’ll need a bootable OSX on CD or USB. For #3 - you might have a bad battery - common if it’s more than 5 years old.
"Screen replacement 21.5 inch A1418 2017 model"に関する回答Any iMac 2012 or newer have the glass and display glued together - unlike older models where the glass was held by magnets and easily replaced. It’s now 7 years after the 2012 model came out and nobody sells just the glass, so they probably won’t due to repair difficulty and low success rate, manufacturing costs, etc. Your only choice is to replace the whole display which is not cheap, but can be found from the usual online markets for less than what Apple would charge.