One of the reasons why I left the (Mac repair) company was because the company owner took a bunch of new jack techs and had them replace the diodes on the PSUs and then sell the repaired PSU as a new one. At $275 for a $2 part and 1 hour of time with a fake "new" label, while claiming to the IIcx (and later ci) owners "It's going to take a week to order the part for you"... - he was making out like a fat rat! In some cases the original PSU was repaired and not replaced and he claimed that it was!

Eventually (many years later that is) his business practices would be caught, and though the company remained in business, he was arrested for unscrupulous and cheating business practices.