Help!..Bizhub C650 color registration is off???

[keystonenew]

On 12x18 or 8.5x11, (text & cover weights), all colors are in registration on top half of the sheet, but gets worse toward the bottom half. The black is a hair lower than the other colors & other colors a off a little, too. It also seems random & varies where it happens on each sheet. Also get a thin, line of color across the width of the paper sometimes. This is on files sent to the rip. We reset the skew adjustment, but still not better. We did print a 12x18 black grid from the glass & all colors register perfectly. Could it be a firmware problem? Any suggestions? Thanks much.

[Stirton.M]

On 12x18 or 8.5x11, (text & cover weights), all colors are in registration on top half of the sheet, but gets worse toward the bottom half. The black is a hair lower than the other colors & other colors a off a little, too. It also seems random & varies where it happens on each sheet. Also get a thin, line of color across the width of the paper sometimes. This is on files sent to the rip. We reset the skew adjustment, but still not better. We did print a 12x18 black grid from the glass & all colors register perfectly. Could it be a firmware problem? Any suggestions? Thanks much.

Don't use black, it will only produce true black. To get all colours, use either 3 colour or 4 colour in grid. You may have to manually set skew adjust for the colours, they adjust themselves to the black set theoretically but this doesn't always work, so adjust the values manually. There is a TSB referenced to this issue, the recommended setting is to have adjust the value below 180, if I recall. Sometimes it can be tough to adjust in grid mode, I use reverse (negative image, black boxes with white lines) to see which colour is skewed.

But what might be the problem is the transfer belt unit itself. We have had a rash of these being damaged. One or more of the first transfer roller holders is broken and the transfer roller itself is not held properly. Simple check, look for loose rollers in the belt unit. You can also swap with another belt unit...doesn't matter the condition...just as long as it isn't broken. Will give you immediate result if this is the problem.

[keystonenew]

Don't use black, it will only produce true black. To get all colours, use either 3 colour or 4 colour in grid. You may have to manually set skew adjust for the colours, they adjust themselves to the black set theoretically but this doesn't always work, so adjust the values manually. There is a TSB referenced to this issue, the recommended setting is to have adjust the value below 180, if I recall. Sometimes it can be tough to adjust in grid mode, I use reverse (negative image, black boxes with white lines) to see which colour is skewed.

But what might be the problem is the transfer belt unit itself. We have had a rash of these being damaged. One or more of the first transfer roller holders is broken and the transfer roller itself is not held properly. Simple check, look for loose rollers in the belt unit. You can also swap with another belt unit...doesn't matter the condition...just as long as it isn't broken. Will give you immediate result if this is the problem.

Thanks mucho & its probably he TB roller holder because its making a vibration noise as each copy prints. Didn't do it at first, but now its making this noise that lasts 3 seconds as the copy goes thru. THanks for the input atain. Buzz

[keystonenew]

Don't use black, it will only produce true black. To get all colours, use either 3 colour or 4 colour in grid. You may have to manually set skew adjust for the colours, they adjust themselves to the black set theoretically but this doesn't always work, so adjust the values manually. There is a TSB referenced to this issue, the recommended setting is to have adjust the value below 180, if I recall. Sometimes it can be tough to adjust in grid mode, I use reverse (negative image, black boxes with white lines) to see which colour is skewed.

But what might be the problem is the transfer belt unit itself. We have had a rash of these being damaged. One or more of the first transfer roller holders is broken and the transfer roller itself is not held properly. Simple check, look for loose rollers in the belt unit. You can also swap with another belt unit...doesn't matter the condition...just as long as it isn't broken. Will give you immediate result if this is the problem.

We've got a Konica tech coming in on Monday, but how can I check the transfer belt on the C650. I've worked on our C500 Pro, & the belt access is from the front. Thanks.

[Stirton.M]

We've got a Konica tech coming in on Monday, but how can I check the transfer belt on the C650. I've worked on our C500 Pro, & the belt access is from the front. Thanks.

While looking at the transfer belt unit from the right hand side door, you will see a metal plate just below it with a black mylar covering it. On the right side of this plate, loosen (do not remove) the thumb screw holding the lock plate. This will allow you to slip the larger plate to the right and remove it.

On the left hand side of the door itself, there is a cable attached to the door with a screw. Release the screw. This will allow the door to sit lower.

There are two metal tabs to the left and right sides of the transfer belt unit that are held in with a single screw. Removing the screw will allow you to pull the metal tabs outwards, (towards you), but they will not off. These are lock tabs for the belt unit itself. Now pull on the tabs of the belt unit and it should slide towards you on a guide rail. Be very careful, any damage to the surface of the belt will show itself in your prints, especially full page solids.

To put back, simply do the reverse order of the above. Again, be careful. Also, before locking the belt in place, make sure it is fully pushed all the way in. The metal plate that sits below it will not sit properly otherwise, nor will the side door close.

[keystonenew]

While looking at the transfer belt unit from the right hand side door, you will see a metal plate just below it with a black mylar covering it. On the right side of this plate, loosen (do not remove) the thumb screw holding the lock plate. This will allow you to slip the larger plate to the right and remove it.

On the left hand side of the door itself, there is a cable attached to the door with a screw. Release the screw. This will allow the door to sit lower.

There are two metal tabs to the left and right sides of the transfer belt unit that are held in with a single screw. Removing the screw will allow you to pull the metal tabs outwards, (towards you), but they will not off. These are lock tabs for the belt unit itself. Now pull on the tabs of the belt unit and it should slide towards you on a guide rail. Be very careful, any damage to the surface of the belt will show itself in your prints, especially full page solids.

To put back, simply do the reverse order of the above. Again, be careful. Also, before locking the belt in place, make sure it is fully pushed all the way in. The metal plate that sits below it will not sit properly otherwise, nor will the side door close.

Thanks again & we'll check it this morning if the tech doesn't show up. Help is much appreciated.

[RRodgers]

Play with the fuser speed. If you are getting what I think you are getting, it's the fuser speed adjustment. BE SURE TO CHANGE IT FOR EVERY WEIGHT OF PAPER, or you won't notice a difference.

[keystonenew]

Re: Help!..Bizhub C650 color registration is off???

How do I go about adjusting the fuser speed when in service mode?

[Albonline]

Re: Help!..Bizhub C650 color registration is off???

fuser speed is controled by a loop ps at infeed guide of fuser. is it working?

[EarthKmTech]

Re: Help!..Bizhub C650 color registration is off???

every "large" office colour machine back to the c350 (and i think even back to the cf2001) will exhibit these symptoms if the fusing loop sensor is gummed up or dirty.

On long papers the fusing unit ends up pulling the paper (due to no loop, but thinking there's a large one and speeding up the fuser) and upsetting the speed at which the transfer belt is rotating, messing up the timing of all colour from half a page on..