Sharp MX 3640N Void areas intermittent

[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.

[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

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

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.

[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

[OlliK1969]

Re: Sharp MX 3640N Void areas intermittent

Hi

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

[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.

[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

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.

[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

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.

[repn1999]

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.

[Ben Around]

Re: Sharp MX 3640N Void areas intermittent

Check your mag roller in the DV unit ...somehow tiny fragments of metal get stuck to the mag roller and that will cause you avoid lines it's really difficult to get it out of there because it's magnetic easiest ways to change it but I have cleaned them before and they have been successful

Sent from my SM-G930V using Tapatalk

Good tip, I'll take a look at that before I return the machine next week.
Thanks.
I hope everyone has a great weekend!

[daileyrobn714]

Re: Sharp MX 3640N Void areas intermittent

Yes, only on black (as far as I can tell). I ran sky shots of each color and could not reproduce the problem.

I've had paper bite me in the behind a few times over the years. So yeah, I wish I would have swapped the paper out, just to eliminate the possibility. But I didn't, so shame on me.

I put a loaner on site and I have the machine in the shop. So I will be looking at it more closely today. It also has an oil resistant squeaky noise in the Doc feeder, so I get rip that apart too.

Thank you everyone for taking the time to respond with suggestions.

Check your mag roller in the DV unit ...somehow tiny fragments of metal get stuck to the mag roller and that will cause you avoid lines it's really difficult to get it out of there because it's magnetic easiest ways to change it but I have cleaned them before and they have been successful

Sent from my SM-G930V using Tapatalk

[Ben Around]

Re: Sharp MX 3640N Void areas intermittent

I've had the machine in the shop for a few days and so far I cannot recreate the void areas.
Environmental? (noisy line voltage), paper? (now spent), loose connection? (cold solder joint) be back to bite me in the a$$? (probably)

At least the doc feeder noise is fixed. Had to remove the paper feed area from the feeder and clean, lube & inspect. It wasn't hard to remove (it looked worse than it was). About 6-8 screws and the whole section comes off. The steps are in the manual, but they only really seem clear after you take it apart.

Thanks to everyone who took the time to reply with helpful comments. I appreciate it.