Dell Lock-In Electronics
Aren't those a joy? I've encountered a failed power supply that, when replaced with a normal PSU, caused the machine to interpret "off" as meaning "turn the fan on, then off, repeat forever". Luckily the machine was just a whipping boy for whatever random job required a box thrown at it temporarily, so it didn't matter.
Then there was the laptop power adapter with the three connections; ground, positive and the connection-to-a-chip-that-identifies-the-power-adapter-as-dell-pineapple-up-the-customers-ass pin. If the laptop couldn't identify the chip properly then the bios would down-clock the CPU by 50%. A normal replacement adapter ran something like $60. The magical Dell adapter was $170 and would have taken a month to arrive. Luckily there was a way to downgrade the bios to prevent it from crippling the laptop on boot.
And let's not forget the conga line of pants-on-head retarded cases that Dell has excreted over the years. Those clam cases were great, opening them felt like pulling the guts out of a fish, opening them all the way caused the IO cables to be ripped out at a 45 degree angle.
Capacitors were another thing that were done The Dell Way. Lots of people got burned in the mid-zeros by crap capacitors, but only Dell (as far as I know) sent out replacement boards they knew would fail almost immediately. Nothing like sending out a box full of motherboards with barfing caps every week only to open a fresh box full of replacement
boards time bombs.