Dadoes is right, F&P top loaders are incredibly simple to work on. Elegant simplicity. The main problem I see on the electronic boards is failed microswitches and they are easily replaced with microswitches from other dead boards.
Miele front loaders I have looked at in the past have also clearly been designed for easy maintenance. Asko too to a degree, though the door switch/lock on mine was a bugger to get at. In the cheaper price front loaders, LG have been very easy to work on in the past.
I have repaired a couple of Bosch front loaders recently and they have been OK, the drum is assembled with dozens of one time only plastic barbs holding the two halves together, but you can split the drum by removing all the barbs with a multi-tool saw, the two halves have unused screw holes and sockets to reassemble with screws instead of the barbs. Apart form the horror of having to remove the whole drum before the disassembly, it was pretty easy. I have recently acquired a Bosch Logixx 8 needing repair, its drum is back to a conventional two halves joined by screws which is better.
I did a couple of Electrolux front loaders last year, they are clearly designed to be as hard as possible to work on, with hidden screws and a truly awful design, I will avoid them in future. These ones have a side seam with a front half and a rear half, no removable rear access panel or simple front panel. Removing either half is a nightmare enough, some tasks require you to remove one half, do some disassembly, then refit the first half and remove the other half. Best binned.