Lexmark- xs748de slow copies and printing

[wyo19]

slow printing and copying on my first visit noticed pcu's were old customer ordered new ones, second visit installed no change if you power off/on speed comes back for maybe 4 or 5 prints/copies then slows down. then plugged into another wall outlet and worked great for about a week. now the problem has returned and going out to check wall voltage, i'm thinking it might be the power supply. any help would be great...

[blackcat4866]

Dying power supply can cause a flickering screen accompanied by a loud buzzing noise, in sync with the flipping. Of fuser codes. Or dead machine. At least those are the things that I've seen. At this age we see a lot of dying or dead XS748DE power supplies. =^..^=