MX-C311 E7-28

[DeanG]

Hi everyone,
I am working on a mx-c311 with an E7-28 code. The book says it is a connection problem between the LSU and PCU. I checked the connection, which was fine, and replaced both the LSU and PCU but I still have the code. Any suggestions?

Thanks,
Dean

[rainmaker]

noticed in the service manual that the LSU mother board could cause it as well as the pcu and lsu you already replaced.So i take it as soon as you power on it goes into the error?

[DeanG]

Yes, I get the code as soon as power is turned on. I replaced the LSU board when I replaced the unit.

[rainmaker]

just checking here to help you out.So you replaced the LSU part#DUNT-8109FCZZ,the PCU part # CPWBX1838FC32,ans the LSU mother PWB part #CPWBX1837DS51?
Did it happen on its own? The error code.The only thing i could suggest is a wiring issue maybe a pinched wire

[dasbrun]

Try clipping all the zip ties on all the wires involved. Used to work on Canon's a lot and that was a common cause of weird issues, the zip ties are cinched down too tight and after time can cause all kinds of weird issues.