Nov 19, 2019 This overview will help you identify a USB power adapter from Apple. When you need to charge your iPhone, iPad, or iPod touch, we recommend that you use the USB power adapter and USB cable that come standard with your device. These adapters and cables are also available separately from Apple and authorized Apple resellers.
Are you getting a chime? Can suggest differential topology hirsch djvu for mac download.
The chime says the computer passed the first part of the Power-On Self-Test, and if enough working RAM and a boot drive can be found, booting is likely. Lack of a chime says something else is amiss.
The usual procedure in cases of no chime is to pretend that something is loading down the power supply. So you remove all the drives and the graphics card and everything except a minimum of RAM, and look for the chime. If you get to the chime, then you add back the graphics card so you can see what is happening, and boot to the Installer DVD. then bring back an item at a time and see when it craps out.
Mac notebook computers come with a USB-C power adapter and charge cable. You can learn which power adapter and cable come with your Mac notebook computer, and find troubleshooting tips below. If you're having an issue with a non-Apple power adapter, try using the Apple power adapter and cable that came with your Mac notebook instead.
If your Mac notebook with USB-C doesn't charge
If your USB-C power adapter isn't charging your MacBook, MacBook Air, or MacBook Pro, first try unplugging the power adapter from the power outlet, waiting a few seconds, and plugging it back in. If that doesn't help, check these things.
Check power
Make sure the USB-C power adapter that came with your Mac notebook is connected to a known working power outlet. Try plugging in a lamp or other appliance to make sure the outlet has power. If you've plugged the power adapter into a power strip, try plugging it directly into the wall outlet.
If the power adapter shuts off, interference might be affecting the power outlet you're using. If your power adapter works for a while, but then stops charging, temporarily unplug it from the power outlet. Wait 30 seconds, then plug the power adapter back in.
If your Mac notebook starts charging after you plug the power adapter back in, this might indicate an issue with line noise (disruption caused by stray electromagnetic signals) from your power outlet. The power adapter automatically shuts off when its built-in voltage protection feature senses line noise from an outlet.
Some possible sources of line noise include lights with ballasts, refrigerators, or mini-refrigerators that are on the same electrical circuit as the outlet you're using. Plugging the power adapter into an uninterruptible power supply (UPS) or an outlet that's on a different circuit can help.
If your power adapter continues to turn itself off when connected to a known good outlet, take your adapter to an Apple Authorized Service Provider or Apple Retail Store for further evaluation.
Your power adapter comes with a removable AC plug that has the blades you insert into an electrical outlet. If your Mac notebook doesn't charge when using the AC plug with the power adapter, try it with another Apple AC plug, or try using an Apple Power Adapter Extension Cable (sold separately).
Check cabling
Your Mac notebook comes with a USB-C cable that charges the computer. You can find out if this cable is causing your charging issue by trying another USB-C cable. Remember, not all USB-C cables can charge your MacBook, MacBook Air, or MacBook Pro, so make sure the cable you try is designed for charging.
If your Mac notebook charges with one USB-C cable but not another, immediately stop using the cable that doesn't work and get your cable and power supply evaluated.
If your Mac notebook begins charging only when you wiggle or move the USB-C cable or Apple Power Adapter Extension Cable (sold separately), immediately stop using the cable and get your cable and power supply evaluated.
Check for updates
In some cases, software or firmware updates might be available for your computer that improve communication with your power adapter. If your MacBook, MacBook Air, or MacBook Pro with USB-C isn't charging as expected, check for software updates on your Mac.
If the adapter gets warm
The USB-C power adapter can become warm during normal use, so be sure to use it in a well ventilated area. Always plug the power adapter directly into a power outlet using the AC plug, or place it on a table or other well ventilated area when using the Power Adapter Extension Cable (sold separately).
Avoid placing your adapter in a poorly ventilated area, like on a couch, thick carpeting, bedding, or a pillow. Avoid covering the adapter with a blanket or other insulation.
The power adapter might turn itself off if it gets too warm. If this happens, disconnect the USB-C cable from your Mac notebook, then let the power adapter cool down before handling it.
If you see a spark
When you plug in the USB-C power adapter, it might spark where the blades of the plug enter the outlet. This is generally normal and can happen when you plug any electrical appliance into a power outlet.
If you see any of the following when you plug in your adapter, or if you have other concerns about sparking, you should contact Apple:
- Contact Apple if a spark comes from somewhere other than the blades of the plug.
- Contact Apple if you see any damage or discoloration on the adapter.
Get your Mac notebook and power supply evaluated
Whether your Mac notebook with USB-C is in or out of warranty, you can bring it to an Apple Authorized Service Provider or Apple Retail Store for evaluation. Be sure to bring your Mac, your USB-C power adapter, and any USB-C cables you use for charging.