Opening Wall Warts (power supplies)

[tomk@pro-nsdapple.cts.com (Tom Kelly)]

Has anyone else taken apart the StyleWriter Power Adapter (Model No:
M8010)?
 
I have three bad ones.  Several months ago I took one apart.
As I recall, I drilled into the three holes on the bottom and pried the two
pieces apart.  I don't recall it being very difficult.
I had a slight problem drilling straight, but recall no other troubles.
Inside there is a transformer, bridge rectifier, fuse, and a few other
parts.
The cause of the failure was a blown fuse (pigtail type).
 
Now I have two more bad ones.  I suspect the same failed part.
When I tried to drill into the holes (like I did before), I am unable to
even scratch what is in the holes.  I even tried to center punch the hole
before I drilled.  I could not put a mark in it.
 
I am at a loss to understand this.
Does anyone have any experience with this?
If so please share how you solved the problem of getting it apart.
 
I am also trying to open and repair a Macintosh PowerBook AC Adapter.
It is Model No:M5651 (APS-20U).
>From its weight I suspect it is a switching supply.
That may make it much harder to repair, but I'd like to get a peek inside
before I give up on it.
Does anyone have any experience with this?
If so please share how you solved the problem of getting it apart.
 
Thanks
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