Why main pcb not power supply (advance copiers)

[mramlawi]

Dears,

i wonder what made the main control in 8105 or 6055 or ir2520 machines the main control pcb dead instead the power supply , knowin that if the electricty got higher the power supply must dead or the main control pcb is weakness and can effected more than the powersupply ? in advance series ?

beacuse it happend with me at my client i was dissabled the finisher in 8105 i turned the machine off the on the black screen with green light on screen , and the machine counter 900,000k and putted on a big ups , that what made me ask also another machine 6055 was the client worked on it before one day and after day he trun it on at the morning he told me that blk screen also i have changed the main pcb 1.

[madas]

Just had a 5000 series do the black screen green light and it was the main controller pcb.

Les