DSM 622 Partial fusing?

[C.Vallon]

Hello guys, I could use a little insight on a reoccurring issue I've been experiencing with a DSM 622 (B089). I've found that within the fusing unit on the left side, the bearing keeps slipping, causing the pressure between the hot roller and pressure roller to be uneven, only on the left side. This of course creates copies with half the toner fused properly and the side lacking pressure, grainy and unfused.

So far I've rebuilt the fuser and replaced pressure roller/hot roller at least twice, yet the issue keeps coming up after every week or two of us. What I usually end up doing is going back up, opening the fuser and slipping the bearing and shaft back in it's proper position. I don't see any damage to the frame or any noticeable damage at all within the unit, yet it keeps slipping and dropping pressure only on that side.

Has anyone experienced this before? Or, any helpful insights/tricks/rigs that may help prevent the problem? I'm headed back out there today to fix it again, while there I will attempt to think of some solution/fix to keep it from happening my self.

Thanks again for any helpful advice.

[sharpmind]

Re: DSM 622 Partial fusing?

Hello guys, I could use a little insight on a reoccurring issue I've been experiencing with a DSM 622 (B089). I've found that within the fusing unit on the left side, the bearing keeps slipping, causing the pressure between the hot roller and pressure roller to be uneven, only on the left side. This of course creates copies with half the toner fused properly and the side lacking pressure, grainy and unfused.

So far I've rebuilt the fuser and replaced pressure roller/hot roller at least twice, yet the issue keeps coming up after every week or two of us. What I usually end up doing is going back up, opening the fuser and slipping the bearing and shaft back in it's proper position. I don't see any damage to the frame or any noticeable damage at all within the unit, yet it keeps slipping and dropping pressure only on that side.

Has anyone experienced this before? Or, any helpful insights/tricks/rigs that may help prevent the problem? I'm headed back out there today to fix it again, while there I will attempt to think of some solution/fix to keep it from happening my self.

Thanks again for any helpful advice.

There is a grip-fusing pressure (green plastic lever) in the left side of the fusing unit which also prevent the ball bearing from slipping. Did you see it?

[C.Vallon]

Re: DSM 622 Partial fusing?

Finished the call today, sure enough it was the same issue. The hot roller and pressure roller had a gap between the two on the one side, causing the toner to become partially fused.

What I did today was readjust the tension/pressure springs, normally the springs set on the first "notch" on the metal frame that also houses the stripper pawls, so I lowered the tension spring to the second "notch" which should force a "tighter" tension between the two rollers, for good measure I added another (though weaker) tension spring above that, in the original position in the hopes to keep the pressure constant. It seems to be holding up after watching it print a 500 page job, no slipping yet.

If this fails, I'll probably try ordering new springs, though the current look, feel and seem to be fine. I really don't want to have to go about trying to order a whole new fuser assembly over a pressure related issue.

[C.Vallon]

Re: DSM 622 Partial fusing?

There is a grip-fusing pressure (green plastic) in the left side of the fusing unit which also prevent the ball bearing from slipping. Did you see it?

I did, and at first thought this was a source of the problem, I've examined it as well as tested it, I don't see it causing the bearing to slip. Though a thought does come to me, on the other side of the pressure roller is a spring/coil that sits on the shaft with the roller, this is on the opposing side of the green lever you mention. If I was to move this spring/coil to the other side, would that make any change in how the pressure is applied?

I ask as I'm wondering if I may have accidentally sit this on the wrong end when I rebuilt the unit, I doubt it as the same issue was happening before the rebuild, though worse. Before it not only had the problem with the pressure being applied, but the hot roller actually melted sections of the pressure roller onto its self. This is what led to the rebuild.

[blackcat4866]

Re: DSM 622 Partial fusing?

Are you using aftermarket fuser rollers? Years back we were using Katun heat rollers on the Adonis Series, and the bearings kept slipping off the frame, losing fixing pressure on one side. The distance between the C-clip grooves was 1.5mm too far apart. My brother works a sheet metal shop, and punched me some special purpose washer/shims 1.5mm thickness x 42mm ID x 47mm OD with a flat on the outside to align with the pressure roller.

Could it be something like that? =^..^=

[Iowatech]

Re: DSM 622 Partial fusing?

I'd check the plastic rib that holds the hot roller bearing in place on the drive gear side. It sounds like that rib is broken and is allowing the bearing to move around.
I seem to remember some people here who replaced those bearings with with ones that have a collar on the outside so that the metal frame holds the bearing in place. Here's that thread, in case it helps:
http://www.copytechnet.com/forums/th...025-fuser.html