Delete comment from: Ken Shirriff's blog
Does anyone know the model/discription of the 8 pin chip inside the 65W apple power unit?
I was careless when I soldered a connector spice in the 18v Magsafe line; the ground shield had one tiny wire strand shorting the output when I powered it back up.
Tips & Info: I successfully replaced my stock apple 18v 65 watt supply with a old Toshiba laptop supply.
So, magsafe/circa 2010 macbook does not care what the power supply is if it keeps up with load.
Then the gold spring pins wore out causing poor power input and the salvaged replacement i bought for about 12 bucks works just fine.
One must do perfect cut and spice and be really careful with every 40 gauge shield/negative strands and strain relief with new magsafe cable and get the right one too. Seems there are at least 3 kinds now.
It's not good to un/plug magsafe while it's powered up because the pins will spark/arc. And wipe clean all contacts often because dust fouls the tiny springs inside!
Anyway, I could fix my apple supply if I replace that mystery chip I just mentioned. It must be a current sense, mos-driver or dual op amp, I hope some reader has more expertise than i do with these COOL running supplys. But,hey forgot a current limit feature. It has most control circuitry I've seen. I'verepaired about 200 kinds of these switching supplys.
Most the time I'm running my mac from a small dc-dc booster from solar battery bank.
The macbook likes 16 to 20 volts on the input otherwise it won't accept charge or power input. It has a tiny shottky diode across the + and _ power input inside and I saw it flash inside through the white plactic case and I replace it yet. It protects the mac from a power reversal but now it's open and fried. Opps again.
best wishes,
dgm
Sep 10, 2015, 12:02:37 PM
Posted to Teardown and exploration of Apple's Magsafe connector