The First MacBook Pro: The Thermal Paste Fiasco
When the MacBook Pro was first launched, representing Apple's introduction of x86 CPUs, it shipped with absurdly large amounts of thermal paste on its chips. This caused overheating issues.
Persons daring to open their MacBook Pro and discover this were able to remove the excessive amount of thermal paste and reseat the heatsinks with suitable quantities of thermal paste, resulting in appropriate cooling.
A service manual was at some point leaked, which advised the reader, when reseating heatsinks, to use a massive amount of thermal paste, something like an entire syringe per chip.
In other words, this represented design-level incompetence, not rectified by servicing. During the design and launch of an x86 laptop, not a single person at Apple was apparently aware of the actual purpose of thermal paste (namely, that it is to ensure proper and even contact between the heatsink and CPU by evening out irregularities in the CPU and heatsink surfaces), seemingly instead believing it to be some sort of magical coolant paste.