The old Comodore computer company had a replacement policy where
you could send the computer to them and they would repair it for a flat
fee.
They had some unskilled labor to open up the case, throw out the
electronics
and install new electronics. The new board cost them $ 50, the repair cost
to customers was around $ 70 to $ 80. Cheeper to throw out the whole
exectronics and replace it than the labor to repair them.

30 years (or so) ago, GE simply replaced defective electronics with a
refurbished unit. The unit you sent in was placed in a pile, to be repaired
at a later date. This probably worked well, if a technician worked on four
or five identical units at the same time.