Yellow gunk inside mid-2007 60W Macbook charger

Question

My mid-2007 white Macbook's charger has stopped working.
I carefully prised it open to see if perhaps a repair might be a simple matter of replacing an obviously worn-out component on the circuit board.
Inside the plastic case and its aluminium (I think) liner, I found the PCB and components wrapped in a triple layer of copper foil, held in place with pale yellow adhesive tape. Once I had carefully peeled back the tape and removed the folded copper foil sheets, I could see the PCB and components. Or at least, I sort of could.
The reason I can't see them clearly is that they are partly covered with even more pale yellow adhesive tape, and also with a large quantity of pale yellow rigid gunk that looks and feels a lot like used, dried chewing gum. I'd estimate that more than half of the volume inside the charger not occupied by components was occupied by this gunk.
I've seen PCBs before that have been "potted" with potting compound (resin), and I've seen PCBs that have had larger components supported with blobs of hot glue or similar in order to reduce stress on the solder joints. This doesn't look like either. I wonder whether perhaps it is some kind of cement designed to give mechanical support, but that the person or machine responsible for applying it got a bit trigger happy! Unless it's some kind of miracle heat transfer compound, then I imagine this gunk might have causd a good deal of overheating within the case of the PSU by preventing convection currents from forming in what would otherwise have been airspace between components.
As for the extra adhesive tape, it seems to have been positioned so as to reduce the risk of metal-topped components (e.g. capacitors, coils) shorting out against the copper foil. If so, only some of the pieces - not all - have been installed correctly: there are a couple of small patches where the copper might have been able to touch a corners of a couple of metal-topped components.
Anyhow, my question: has anyone else found their charger to be full of gunk like this, or is mine abnormal?

Answer 1

Sorry for the long delay. Here is a photo of the charger, and one of the first layer of insulation and shielding (showing the inside). I note that the first layer of insulation/shielding has a scorch mark at the spot that had been closest to the component bolted to the heatsink near the top right of the circuit board (see arrows). That component seems to have three legs, so I guess it might be some kind of power transistor or voltage regulator.
And here are some photos showing the hardened gunk more clearly:
As you can see, it's a lot of gunk! Any ideas/explanations/suggestions gratefully received...