c308 error code E4-2, no black color.

[Sanker]

A client called couple days ago and said that printed documents have black background stripes (see attached picture 1). Need to mention that night before the call there was a storm with lightnings. Also this client uses not OEM toners but we didn't had any problems yet with that kind of toner on these bizhub model.
First thing i did is replacing Black IU because it was in a bad condition. After i replaced that, things went worse (see attached picture 2).
Then i did self diagnosis and it showed "E4-2 error" which means according to service manual bad DIMM or MFPB. Also codes P-5, P-9, P-21. I couldn't believe that, because we had similar problems in older bizhubs and usually there were bad solenoids/clutches, HV boards, DEV units and so on. Things i've already replaced:
1) Black IU
2) Black DU
3) HV Board
4) Solenoid behind HV Board
5) Transfer belt (after i did that, black color almost vanished, see picture 3 and 4)
5) DCPU board
6) FRB board

Looking for an advice before ordering an expensive MFPB, maybe somebody already had that problem and could share the solution. I will be grateful for any suggestions.

Similar threads i've checked but there is no solution mentioned:
- bizhub C454e no black color
- Bizhub c308 no Black


1.jpg2.jpg3.jpg4.jpg

[Bricorley]

If you have a spare C308 you can board swap just for testing... at lease they say you can.

[Phil B.]

A client called couple days ago and said that printed documents have black background stripes (see attached picture 1). Need to mention that night before the call there was a storm with lightnings. Also this client uses not OEM toners but we didn't had any problems yet with that kind of toner on these bizhub model.
First thing i did is replacing Black IU because it was in a bad condition. After i replaced that, things went worse (see attached picture 2).
Then i did self diagnosis and it showed "E4-2 error" which means according to service manual bad DIMM or MFPB. Also codes P-5, P-9, P-21. I couldn't believe that, because we had similar problems in older bizhubs and usually there were bad solenoids/clutches, HV boards, DEV units and so on. Things i've already replaced:
1) Black IU
2) Black DU
3) HV Board
4) Solenoid behind HV Board
5) Transfer belt (after i did that, black color almost vanished, see picture 3 and 4)
5) DCPU board
6) FRB board

Looking for an advice before ordering an expensive MFPB, maybe somebody already had that problem and could share the solution. I will be grateful for any suggestions.

Similar threads i've checked but there is no solution mentioned:
- bizhub C454e no black color
- Bizhub c308 no Black


1.jpg2.jpg3.jpg4.jpg

You replaced the K IU and things went to hell, why didn't you retrace your steps? Why spend all that time swapping parts?
Logic tells me something in your first 'repair' went screwy.

Sent from my SM-G960U using Tapatalk

[tsbservice]

I can't believe you swapped ALL that parts with NEW on cheap customer's machine.
The fact you've replaced consumables like drum and TBU and machine went crazy is telling me it's pushed to far. Can you provide MML? I would check ribbon connectors of PH unit plus swap it if possible.

[tech51]

You will always get an e4-2 error on diagnostics unless you have an extra memory module mounted so I think that maybe leading you in the wrong direction.

I once fitted a new drum to a c458 that caused a black background. Turned out that the contact to the charge roller was poorly made.
I reformed and cleaned the contact and all was well afterwards so don’t rule out the fact that the drum you fitted could be faulty.

[Sanker]

You replaced the K IU and things went to hell, why didn't you retrace your steps? Why spend all that time swapping parts?
Logic tells me something in your first 'repair' went screwy.

Sent from my SM-G960U using Tapatalk

If you read full description of the problem your logic must tell you different because i wrote that we had similar problems with other machines and it's not my first "repair", friend. Thank you for your help, have a nice day.

[Sanker]

I can't believe you swapped ALL that parts with NEW on cheap customer's machine.
The fact you've replaced consumables like drum and TBU and machine went crazy is telling me it's pushed to far. Can you provide MML? I would check ribbon connectors of PH unit plus swap it if possible.

You are right, most of the parts weren't new.

Thank you for your help. I've sent it to you, check PM.