Sharp MX 3640N Void areas intermittent

[Ben Around]

Re: Sharp MX 3640N Void areas intermittent

I had a mx3140 do the exact same thing on black only. turned out to be primary belt...not the unit just the belt itself. looked it over closely and since outside was perfect i cut it in half and found a small scratch through the back surface of the belt. machine has been in field for about 2 years since that issue and it has never came back.

Thanks for adding that info.

[romang]

Re: Sharp MX 3640N Void areas intermittent

Did you fix thia already? Im curious what fixed it. Looked liked charge or dv unit shorting

[Ben Around]

Re: Sharp MX 3640N Void areas intermittent

Did you fix thia already? Im curious what fixed it. Looked liked charge or dv unit shorting

I was not able to recreate the problem when I brought the machine to the shop, so I was unable to isolate & identify the cause.
When the machine was at the customer location and the problem was still occurring, I swapped the black drum unit with a good one. The drum unit change did not correct the problem. So all I know for sure, is that it was not a drum unit problem. I also checked (and cleaned) the laser glass very carefully, so it was unlikely that the voids were from foreign object debris in the laser path.

So far the voids have not come back.

[harps05]

Re: Sharp MX 3640N Void areas intermittent

I'm having the same problem on a MX3640.

Only happens on the second half of A3 Black pages. (See samples below). Cannot replicate with single colours. Image is on the transfer when stopped mid print.

Machine is at about 450k with regular servicing.

Paper is 75gsm.

Have tried the following:
Replaced Primary Transfer Unit
Replaced Black Drum and Charge
Tried another Dev unit
Replaced Laser Unit
Tried different power outlets.

A3 issue.pdfA3 issue 2.pdf

[Ben Around]

Re: Sharp MX 3640N Void areas intermittent

That looks like the same problem I was having. I was not able to isolate the cause. I removed the machine from the customers location and brought it to the shop. I was not able to recreate the void problem again. I returned the machine to the customer and have not had the problem again.

I hope you are able to figure this out. I would really like to know the cause.

[OlliK1969]

Re: Sharp MX 3640N Void areas intermittent

Hi

have had this error and change second transfer unit. There was a clutch faulty.

[harps05]

Re: Sharp MX 3640N Void areas intermittent

Hi

have had this error and change second transfer unit. There was a clutch faulty.

Thanks OlliK,

I haven't been back to site yet, I will see on Monday (Installs all day today). I have a spare unit here. So I will fit and report.

Thanks mate

[harps05]

Re: Sharp MX 3640N Void areas intermittent

Hi

have had this error and change second transfer unit. There was a clutch faulty.

Unfortunately, replacing the Secondary Transfer Unit didn't resolve this issue. Will keep head scratching for now.

[copiertec]

Re: Sharp MX 3640N Void areas intermittent

Unfortunately, replacing the Secondary Transfer Unit didn't resolve this issue. Will keep head scratching for now.

There was a TSB a while back about removing the LSU shutter, I really can't think of too much more besides checking all the connectors on the black drum unit and developer units and making sure you have a good ground. It's strange that it only happens on black.

[harps05]

Re: Sharp MX 3640N Void areas intermittent

There was a TSB a while back about removing the LSU shutter, I really can't think of too much more besides checking all the connectors on the black drum unit and developer units and making sure you have a good ground. It's strange that it only happens on black.

Yeah, because of the weird, random, definition of the marks on the prints I'm thinking it's obviously a charge irregularity somewhere. And as the Primary Transfer, Black Dev unit and Black Drum unit has been swapped and tested with the problem remaining, I'm thinking that as much dicking around that it's gunna be, I think I may have to swap the HV PWB's for the main charge and transfer as the units replaced initially get the charge from these components.

So what's that now:

Primary Transfer Unit
Black Drum and Charge
Dev unit
Laser Unit
Different power outlets
Secondary Transfer Unit

+ possibly

2 x HV PWB's




Geez I hate going back to a place looking incompetent.

[copiertec]

Re: Sharp MX 3640N Void areas intermittent

Yeah, because of the weird, random, definition of the marks on the prints I'm thinking it's obviously a charge irregularity somewhere. And as the Primary Transfer, Black Dev unit and Black Drum unit has been swapped and tested with the problem remaining, I'm thinking that as much dicking around that it's gunna be, I think I may have to swap the HV PWB's for the main charge and transfer as the units replaced initially get the charge from these components.

So what's that now:

Primary Transfer Unit
Black Drum and Charge
Dev unit
Laser Unit
Different power outlets
Secondary Transfer Unit

+ possibly

2 x HV PWB's




Geez I hate going back to a place looking incompetent.

Ah, the joys of being a tech, I know the feeling.