Lexmark E323 Fuser Replacement

Fuser replacement in the E323 is complicated somewhat by the need to remove the charge roller for access to the fuser. Also, the thermistor cable is strung clear across the machine underneath. The bottom pan must be removed to get at it.

1) Cartridge

2) Top Cover
> Two M3x10mm pan head threading screws.

3) Right Side Cover
> Two finger-operable claws in front.

4) Left Side Cover
> One M3x10mm pan head threading screw.
> Two claws in front.

5) Controller PCA Cover
> Four M3x6mm YZD hex washerhead screws.

6) Thermistor Cable at Controller PCA
> Two-conductor cable connection at J14. (Lexmark's service manual claims that there are two thermistors in the E323. The second thermistor allegedly connects to a 'J22'. We know of no such second thermistor.)
> Free the cable from the clamp.

7) Bottom Pan (to free the thermistor cable entirely)
> Set the printer on its back.
> One M3x6mm YZD hex washerhead screw at the left rear.
> Three M3x10mm YZD washerhead threading screws.
> Drop the pan.
> Extract the thermistor cable and temporarily reattach the bottom pan for now. You'll need to open it up again to restring the new fuser's thermistor cable.

8) Controller PCA w/Enclosure
> Thirteen cable connections. Free the cables from the enclosure.
> Three M3x6mm YZD hex washerhead screws outboard of the enclosure.
> Two M3x10mm YZD washerhead threading screws at the upper edge of the PCA.

9) Fan
> Two M3x18mm YZD hex washerhead threading screws.
> Let the fan dangle.

10) Fuser Top Cover
> Two M3x10mm bright pan head threading screws.
> Pry gently in back of the two torsion springs to free the cover.

11) White Charge Roller Clips
> Remove the clips to free the charge roller from the door-mounted levers. Let the charge roller swing over and rest behind the fuser.
> NOTE the different-coloured torsion springs; the brass-coloured spring is at the left.

12) Torsion Spring Ends
> Unhook them to relax their tension somewhat.

13) Charge Roller Pivot Retainers
> One claw at each. Pull them off.

14) Charge Roller Assembly
> It's now possible to free the left side pivot arm, and then the entire assembly.
> Note the pre-tensioned installation of the torsion springs.

15) Fuser Heater Wires
> Two spade terminals.

16) Fuser Ground Wire
> One M3x10mm YZD washerhead threading screw.

17) Fuser
> Free the thermistor cable from the cable clamp nearest the fuser.
> Two M3x10mm YZD washerhead screws.
> Two claws in front.

You'll need to remove the top cover from the replacement fuser before installing it.

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Lexmark E323 Pickup Roller Replacement

The E323's pickup roller is a complete shaft/cams/roller assembly that's replaced as a unit.

The following procedure also removes the lower registration roller so it can be cleaned.

1) Cartridge

2) Top Cover
> Two M3x10mm pan head threading screws.

3) Right Side Cover
> Two finger-operable claws in front.

4) Left Side Cover
> One M3x10mm pan head threading screw.
> Two claws in front.

5) Rear Cover
> Two M3x10mm pan head threading screws.
> NOTE that the separation pad is now accessible for replacement.

6) Controller PCA Cover
> Four M3x6mm YZD hex washerhead screws.

7) Controller PCA w/Enclosure
> Fourteen cable connections. Free the cables from the enclosure. NOTE that connector J19 is unused.
> Three M3x6mm YZD hex washerhead screws outboard of the enclosure.
> Two M3x10mm YZD washerhead threading screws at the upper edge of the PCA.

8) Paper Input Chute
> One M3x6mm YZD hex washerhead screw at the ground continuity strap.
> Two M3x10mm YZD washerhead threading screws.
> Tip the chute rearward. Don't try to remove it entirely.

9) High Voltage Power Supply
> One cable connection at the top edge.
> Four M3x10mm YZD washerhead threading screws.
> Six 'bullet' contacts w/springs.

10) Main Drive Train
> Tray 2 bulkhead connector. Two claws. It lifts up out of its bracket.
> Free two cables from the cable clamp at the rear.
> Free the cabling from the cable clamp at the front.
> Four M3x10mm YZD washerhead threading screws.

11) Pickup Clutch
> One claw.

12) Pickup Roller
> Two swing-latch bearings.
> Tip the paper input chute forward a bit, and you'll be able to shift the roller shaft rightward to free its left side end.

13) Upper Registration Roller/Gate Assembly
> One swing-latch bearing.

14) Registration Idler Gear
> Slip it off its spindle.

15) Lower Registration Roller Gear
> One claw.

16) White Bearing
> Slip it out.

17) Lower Registration Roller w/Bearings
> Pry it upward and it'll pop out.

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Oki 320/1 Turbo, 420/1 -- Menu Mode Unavailable

If you can't get at the Menu Mode by pressing SHIFT + MENU, it's likely because the Operator Panel Function item in the menu has been set to Limited Operation.

Load continuous forms and switch off the printer. Power on while holding SHIFT + MENU. The printer will come up in Menu Mode. Operator Panel Function is an item in the Set-Up group. Change it to Full Operation to restore complete functionality.

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Label Sheet Feeding

Sheets of labels can be troublesome for pickup rollers because of their relatively slick surface on the back. Even new pickup rollers can experience traction failures on them. There is some traction force adjustability in Lexmark's autocompensator arms that may help. Here's a view of it in a T640 add-on tray.

The light spring that extends down the upper side of the autocompensator arm is a counterbalance spring. It's there to limit the pressure the pickup tires can exert when they're turning, so that multiple pickups don't occur.

Note the clip that anchors the end of the spring -- that clip's position is the adjustment. The clip in the photo is set at design centre.

For trays that feed label sheets, move the anchor clip to its uppermost/rearmost position, as in the following photo.

That minimizes the spring's counterbalancing effect, maximizing traction. (On the T640 and T650 integral trays, the clip has been deleted; there's a series of holes along the top of the arm that provide the same adjustability.)

I ran the pictured tray with ordinary paper after adjusting it for maximum traction, and had no double-feeding occur.

For label sheets, it's also wise to avoid third-party pickup rollers. From what I've seen of them, they just don't have the traction of the OEM parts -- either 40X0070 or 40X4308.

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FEEDBACK

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Epson DFX-5000+ Label Jam Notes

We had a machine come in that had been printing 2" x 4" tractor-fed labels. A label was stuck to the face of the ribbon mask, and to the rear suface of the spring-loaded tension plate below the platen. Following are a few notes on how the clean-up went.

a) Ribbon Mask:

The ribbon mask is attached to the printhead by two studs with screwdriver slots in their ends. The one at the left had a broken slot. When I got the complete printhead out and looked at the ribbon mask's attachment, it appeared that the left side stud had been cemented in place at the factory. Why they would do that is beyond me, but it's something to be mindful of. If you go to remove a ribbon mask stud and it can't be loosened easily, stop; you'll just break the screwdriver slot if you keep torquing it harder. Take the whole printhead off and see what you're up against.

Wetting the stuck label with Varsol was helpful for getting it off.

A good feature of the printhead/carriage is that the printhead is self-positioning as it's put back on the carriage. Removing and reinstalling the printhead won't alter the printhead/platen gap adjustment.

b) Tension Plate:

It would have been nice to have removed this item to get the label off of it, but it looked like something I might not be able to get back in without tearing down the whole machine.

I took a sheet of paper towel, folded it in four, dipped it in Varsol and placed it behind the tension plate where the label was stuck to it. After about half-an-hour, the label came away easily. Varsol is a fairly benign solvent, so it did no harm to the adjacent plastic parts.

All-in-all, a good outcome. That Varsol soak saved a lot of work and gave a good result.

(From what I've observed, not all label adhesives are the same. In a case where Varsol is ineffective, try methyl hydrate. It's also relatively benign and won't harm plastic.)

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