Incredibly slow performance. Possible hardware error?
My friends daughter has an MacBook Air "Core i5" 1.6 13" (Early 2015) A1466 EMC 2925.
A couple of days ago they wanted me to have a look at it to see why it was so slow.
I looked at the obvious stuff. Activity monitor and Disk Utillity.
The disk reported 18MB free, but it seemed odd. There was almost nothing stored at the machine. I took my Daisy-disk tool, to have a look at it. Then it was suddenly 100GB free. When I looked in the D-U, it suddenly shows 100GB free.
But no matter what, the performance is poor..
If I unplug the power cord, it could make the machine to have a blackout.
When the power is in, I have to hold down the power button, and wait for the Chime to be finished before I release it, or else it just dies.
On battery, this is not the case.
When trying a macOS sierra fresh install with wiped disk, it took 7 hours to install! And after that it dies. The only way to boot again is to remove/re-plug the battery and than it's all fine. But the performance is totally useless.
Are there anyone having some suggestions what might be wrong?
I cannot see any signs of water. And I believe the system is out of warranty at this point.
Is this a good question?