I happened to buy an old MacBook and it came with an unreliable MagSafe power adapter.
How can Apple, after producing this general style of AC adapter for over 15 years, manage to continue to make a power adapter that fails? More confounding, I've purchased a number of MacBooks over the last decade, and I have never had a problematic MagSafe power adapter. What gives?
The simple answer is: Customer Abuse.
I've actually had my hands on at least 10 broken MagSafe power adapters, and in every single case the failure was caused by customer misuse. Here is the list of failures I've seen:
- Cat or Dog chewed cable
- Pinched cable (crushed from furniture or a door or something)
- Over-stressed cable (from repeated yanking, over-winding, or some other abusive behavior)
So, what do I do about it? My answer is to replace the cable!
- Remove the power cable or duckhead from the MagSafe adapter
- Crack open the MagSafe adapter using large needle-nosed pliers
- Remove the old cable using solder wick and soldering iron.
- Solder in new cable
- Close the MagSafe adapter, lashing with tape
- Verify proper operation with a voltmeter
- If successful, use epoxy to re-seal the MagSafe adapter
That concludes what I do with a misused MacSafe adapter.