Lexmark X264dn -- LVPS/HVPS Removal

We had to replace one of these recently to solve a 'blank prints' problem; the machine was printing entirely blank pages with no error indication. The prints exhibited a slight bit of grey background.

Part number is 40X5361 (110V).

The unit resides above the paper tray cavity at the rear of the printer. Proceed as follows:

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1) Cartridge

2) Paper Tray

3) Rear Door
- Open it to about a forty-five degree angle, and tug forcefully to pop it off its hinges.

4) Rear Cover
- Two M4x8mm bright washerhead threading screws.
- Pry to free its upper edges at left and right.
- Tip it out and lift its lower hooks off their perches.

5) Front Scanner Cover
- Tug/pry on it. Its four concealed claws will pop free.

6) Left Side Scanner Cover
- One M3x8mm bright washerhead threading screw at the front.
- One M3x8mm bright washerhead threading screw at the rear.
- Tip the bottom of the cover outward to free the cover.

7) Lay the machine on its right side.

8) Left Side Cover
- One M3x6mm bright washerhead screw at lower front.
- Two claws underneath.
- Tip the cover outward and force it upward to free two hook-tabs at the cover's upper lip.

9) Fuser Power Connector
- Two-conductor black cable connection at left side, lower rear.

10) Right Rear Foot
- Two M3x6mm bright washerhead screws.

11) LVPS/HVPS
- Four M3x6mm bright washerhead screws -- two underneath; two at the rear.
- One white-shelled spade connector at left side.
- Three cable connections at PCA.

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Lexmark Optra E310 -- Pickup Roller and Separation Pads Replacement

It's a straightforward job, but it's quite a teardown to get at the parts.

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Part Numbers

Pickup Roller Assembly: 12G0067

Main Separation Pad: 12G0062

Left Side Sub-Pad: 12G0119

Right Side Sub-Pad: 12G0120

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Proceed as follows:

1) Front Face-Up Delivery Door
- Unlatch it, and flex it to remove it from its hinges. This is done to make it easy to dislodge the front door when needed. The door interferes with removing the left and right side covers.

2) Cartridge

3) Rear Cover
- Three M3x10mm bright washerhead threading screws.
- Two claws.
- Force the cover upward a bit to unhook it.
- AT REINSTALLATION, mind the parallel interface connector's bails.

4) Top Cover
- Two M3x10mm bright washerhead threading screws.
- The cover lifts away easily.

5) Left Side Cover
- One M3x10mm bright washerhead threading screw at the lower rear.
- One M3x10mm bright washerhead threading screw securing the door's restraint strap.
- One claw next to the printhead.
- Pry at the lower rear to free a retaining nub from a hole in the chassis.
- The lower front is held in place like the lower rear is. The door makes it a bit awkward to get the lower front freed. Dislodge the door's hinge if needed to get the cover off.

6) Right Side Cover
- One M3x10mm bright washerhead threading screw at the lower rear.
- Similar to left side cover.

7) Paper Supply Chute
- Lift it out.
- AT REINSTALLATION, watch that the black mylar sheet in front goes straight into place, and won't interfere with paper motion.

8) Motor/Drivetrain Assembly
- Note the wire and strap connections, and the 'Z'-shaped cable retainer.
- Six M3x10mm black washerhead threading screws.
- Pull the assembly out a way.
- One cable connection at motor.

9) High Voltage Power Supply (HVPS)
- Three cable connections at the upper edge.
- Five M3x10mm black washerhead threading screws.
- Pull the HVPS out a way.
- One cable connection.

10) Spring-Loaded 'Bullet' Contacts
- With the HVPS removed, four contacts are free to come out. Remove them for safe keeping. NOTE that the lower one of the four has a longer spring on it.

11) Printhead w/Mounting Deck
- This item can't be removed entirely because of the way that it's cabled, but it needs to be moved aside for access to the paper pickup area.
- Six M3x10mm black washerhead threading screws, three per side.
- There's a 'hole & stud' retention in front of the fan. Free that and the unit can be lifted away, and lain down behind the printer.
-REASSEMBLY CAUTION: The two upward-pointing 'ears' on the pickup roller assembly must end up in front of the lower rear ledge of the printhead deck. The printer will not feed paper otherwise.
- CHECK that the pickup solenoid's flapper hasn't been dislodged after reassembly.

12) Lift Plate Springs
- Unhook them.

13) Pickup Clutch
- One e-clip.

14) Left Side Pickup Shaft Bearing
- Black plastic 'rectangular' baffle plate -- a springy claw is securing it.
- One M3x8mm black pan head threading screw at the ground contact strap.
- Swing-latch bearing -- remove it.

15) Pickup Roller Assembly
- Shift it rightward, free its left side end and remove it.

16) Lift Plate
- Raise it until the flats on its right side pivot pin permit it to come out and away.

17) Main Separation Pad
- Tip it up to where it can come out.
- TRANSFER the spring to the relacement pad.

18) Left and Right Sub-Pads
- A slim spring hook is helpful for unclipping their lower rear edges.

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Lexmark X544 -- Fuser Removal

Fuser removal in the X544 is not pleasant. You'll need a spring hook. Proceed as follows:

1) Paper Tray

2) Front Door Open

3) Flatbed Scanner
- Raise it. There's a latch-button at the right side with a 'toner' symbol on it. Squeeze that and lift firmly. The flatbed will lift and latch. Squeeze the button again when you need to unlatch and lower the flatbed.

4) Right Side Cover
- Press two green buttons. The cover swings down and comes away from its hinges easily.

5) Left Side Cover
- One M3.5x6mm pan head threading screw in centre of handgrip.
- One M3.5x6mm pan head threading screw below line cord receptacle.
- One M3x6mm washerhead screw above and inboard of line cord receptacle.
- One M3.5x6mm pan head threading screw by upper outboard corner of fan.
- Flex the cover outward below and behind the on/off switch to disengage a tab at the bottom front of the cover. The cover can then be fully eased off.

6) Fuser Power Cable
- Disconnect blue and white cable from rear of power supply at left side of printer. Free the cable from its restraint.

7) Fuser Frame Screw
- One M3.5x9mm pan head screw w/captive washer directly above fuser motor.

8) Thermistor Cables
- Two small two-conductor cable connections at right front of fuser; one black, one white.

9) Timing Belt
- CAUTION: Try to disturb this belt as little as possible when dealing with it. Should it get dislodged from its path inside the machine, you could be in for an ordeal. NOTE that it's toothed on both sides.
- It's at the extreme upper left of the fuser. Dislodge it from its pulley; you'll have to pry it off with a small screwdriver.
- AT REINSTALLATION, you'll need a spring hook to get the belt back in place.

10) Retention Springs
- There are two extension springs securing the upper ends of the fuser's frame. Unhook them.
- AT REASSEMBLY, make sure the springs are perched upright so they can be hooked for reattachment.

11) Exit Sensor
- Tip the fuser outward. At the sensor's underside there's a thin black retention plate. Pry that off and the sensor can be freed from its cut-out in the sheet metal.
- Free the sensor's cabling from the fuser's frame.

12) Fuser
- Tip the fuser out fully, slide it leftward a bit and it can be lifted off the rod that it pivots on (note the flats). Coax the blue and white power cable out along with the fuser.
- NOTE that at reassembly, the blue and white power cable goes inboard of the fuser's pivot rod.

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Oki PM 3410 -- Revisions 'A' and 'B' Power Supply Replacement

A Pacemark 3410's revision level is given by the fourth character of the printer's serial number. If you have a revision 'A' or 'B' printer that needs a power supply replacement, you'll have to get a revision 'C' power supply (P/N 42312551); the earlier revisions are no longer available. There's an issue of connector compatibility that arises with that; there are two ways to deal with it.

a) Replace the two cables that connect to the power supply with revised, compatible cables. The part numbers are 41998701 (9 pin cable) and 41998801 (13 pin cable).

Obtaining those cables might be problematical. We tried recently to get a set, and Oki couldn't come up with them.

b) Swap the two connectors involved on the power supply. The circuit boards are of simple, cheap construction without thru-connects, so it's very easy to unsolder components without harm to the board.

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The mechanism has to come out of the chassis pan for access to the power supply. Proceed as follows:

1) Access Cover
- Tip it up from the rear. When it's fully opened, it can come away.

2) Platen Knob

3) Pull-Up Roller Assembly
- Open the upper rear acoustic cover.
- Tip the pull-up roller assembly rearward to unclip it.

4) Top Cover
- Two M4x10mm bright pan head screws w/captive washers at the rear.
- Tip the cover up from the rear and it unhooks easily from the front.
-NOTE: The two nuts for the M4 screws sit loose in pockets. They're easily dislodged and lost. Best to remove them with a magnet and keep them with the screws.

5) Ribbon Cartridge

6) Control Panel w/Sheet Metal Mount
- One ZIF cable connection -- CN10.
- Five M3x6mm washerhead screws.
- Two cable connections -- CN11 and CN12.

7) Mechanism Cabling
- Two cable connections high up on interface connector PCA -- CN102 and CN103.
- Line feed motor connection at lower right of PCA -- CN9.
- Fan connection -- CN8. Check that this cable is free of other cabling.
- Two carriage motor connections -- CN1 and CN5.
- Carriage cable connection at upper edge of PCA -- CN2.
- Cable connection at lower left side of PCA -- CN4.

8) Mechanism
- Mechanism base fasteners -- three M4x12mm pan head screws w/captive washers, plus three steel clamp-plates. A magnetic retrieval tool is helpful.
- Mechanism rear edge fasteners -- three M4x8mm pan head screws w/captive washers.
- The mechanism is free to be lifted out of the chassis pan.

9) Power Supply
- Two cable connections.
- Four M4x8mm pan head screws w/captive washers.
- The unit's rocker switch, and a sheet metal projection at the lower right rear can be a bit of a hindrance to unit removal. Lift the left side end of the power supply slightly and it comes out easily.

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If you have the replacement cables, it's pretty obvious how the old cables are removed and the new ones are installed.

If you're swapping connectors, the connectors can be removed without dismounting the circuit boards from their frames. To dismount a circuit board to make connector installation easier, remove the insulation sheet and six screws. There are two cable connections to be disconnected.

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Lexmark T65X -- MP Feeder Booby Trap

I had the MP Feeder lift plate assembly off a T652n to get at a label that was stuck in the infeed chute. When I put it back on and went to test the machine, the MP Feeder was inoperative. It turned out that I'd dislodged the MP Feeder solenoid's flapper, like so.

It's really easy to do that. Be careful when you're in that area, and confirm that the flapper is ok before buttoning things up. Here's a view of the flapper seated correctly.

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The 'Training' Fallacy

In the printer service field, we hear endlessly about technician 'training' and technician 'certification'. There's an outfit known as CompTIA^[1] that's spun quite a business out of that theme -- the PDI+ rack..., er, 'certification'.

If I may be blunt, 'training', as it's commonly understood and practised, is a worthless load of rubbish, unfit for human consumption. 'Training' is for puppy dogs, to acquaint them with the idea that they're not to shit inside the house. One cannot 'train' a technician to diagnose and correct printer troubles in any such fashion. The notion is patently false, ludicrous and an insult to technicians' intelligence.

With that little rant out of the way, I'll elaborate.

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On this blog, I post information and instruction; information and instruction in plain English that I can vouch for because I've personally verified every word of it. Information and instruction that some have found to be helpful. Here's a small example. It's a brief post I did about getting an Okidata printer's full control panel functionality restored when it's been suppressed:

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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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Here's the response I got to that from 'Anonymous':

AnonymousNov 12, 2011 09:06 AM

thank you!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

AnonymousNov 12, 2011 09:17 AM

thank for ending 2 weeks of endless searching, and im the tech savey one here

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My point here is that Anonymous did not need 'training'. What he needed was information. Given that information, he was able to solve his problem and move on.

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Conventional training, by and large, is neither informative nor instructive. It consists chiefly of shallow 'data' that leaves its recipient no more enlightened about the subject matter than before.

The PDI+ programme is accompanied by a massive PDF 'textbook' that purports to teach printer service. The book spews all manner of 'data' without ever connecting that data to the problem of diagnosing and correcting printer faults. One is told how the machines work. One is not told how the machines 'work' when they're not working right, and how they work when they're not working right is what the technician is grappling with all the time.

The textbook tells of rollers; e.g. pickup rollers that get a sheet of paper launched out of a paper tray. Consider, what is the quality that such a roller must possess in order to function reliably? It must possess traction. I did a search through the entire book for an occurrence of the word 'traction', and the word appears not once. A discussion of rubber rollers that fails to even once mention 'traction' reveals itself to be a hollow fraud.

The textbook tells of clutches. Clutches of various types are widely used in printers, and they're prone to intermittent failure as they age and wear. They tend to cause mystifying trouble symptoms. The book offers no information about clutch failure mechanisms, about how those failure mechanisms express themselves or about how to identify and isolate clutch failures.

A technician can study the textbook, sit and pass the multiple-choice exam and be certified without ever having really learned anything that would help him repair a malfunctioning printer. The training and certification testing are worthless. Actually, they're worse than worthless because they consume resources to no good effect that could could be put to profitable use.

Here's an example of the sort of printer service that all too often transpires in the field. I don't know whether the original technician on the call was PDI+ certified or not, but the outcome he got was about par for many technicians, certified or not. We see this sort of thing quite routinely.

Last week, a computer service firm brought a LaserJet 4200 to our shop that they'd tried and failed to fix. The problem was intermittent paper jams. They'd replaced many components to no avail; they'd even replaced the DC Controller. I took the right side cover off and removed the tray 2 pickup solenoid to examine it. The solenoid was sticky, as described in this post. The repair method described in that same post got the machine working reliably. The knowledge I used to effect that repair did not come from CompTIA, or from any of the OEMs.

If CompTIA means to be helpful with its PDI+ programme, it needs to rethink 'training' from the ground up, and investigate what printer troubleshooting and repair actually consist of. For starters, they could purge that word 'training' altogether, and leave 'training' to those who have puppy dogs in need of housebreaking.

Alternatively, CompTIA could just go away, and cease burdening working technicians with its demonstrably worthless 'training' and 'certification' programme.

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Note:

[1] I don't mean to single out CompTIA here. All of the OEMs' 'training' adheres to the same witless orthodoxy, and is equally a waste of time and resources.

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Lexmark T64X -- 500-Sheet Add-On Trays

There appears to be two versions of outfeed pinch roller tensioning in the T64X 500-sheet trays.

There's what I take to be an earlier version, where the tensioning method is the same as it was for preceeding T models. There's also a simplified version. This post explains the operation of the earlier type, and shows a modification to enhance its reliability. This post gives the teardown procedure for the trays.

In the simplified version, the drawer-actuated tensioning lever has been deleted. The pinch roller is always tensioned; there's no lever to jam and break.

We've seen several of the earlier T64X trays lately with broken tensioning levers. The fault is easy to spot -- the pinch roller (the smaller roller in front) has no tension against the outfeed roller at all; you can see daylight between the rollers. Here's a view inside of what's happened in those cases.

The lever has snapped. The spring has jumped off its hook on the lever. Pinch roller tensioning is completely inoperative -- the tray will not feed.

To fix this, first pry the lever remnant off from below with a long, slim-bladed screwdriver. Then get the loose end of the spring hooked over the lever's spindle and tensioning is restored. (Getting the spring end in place is easier said than done, but it is doable. You have to distort the loop at the end of the spring a bit to get it to fit over the spindle. Here's a view of a completed tensioning repair.

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HP LaserJet 2300 -- Add-On Tray Pickup Roller Access

Pickup Roller P/N is RB2-6304.

The roller is accessed from below. There are two plastic covers concealing the roller's swing-latch bearings. For a 500-sheet tray, proceed as follows (250-sheet is similar):

1) Tray Unit less tray upside down.

2) Front Sheet Metal Cross-Member
- Two M4x10mm bright washerhead threading screws.

3) Left Side Bearing Cover
- One claw at inboard rear corner.

4) Right Side Bearing Cover
- One claw at inboard centre.

5) Left Side Bearing
- Unlatch and remove it.

6) Right Side Bearing
- Unlatch and slide it rightward over the shaft.

Here's a view of the roller ready to be removed.

Don't forget to transfer the two slip rollers over to the new pickup roller.

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Lexmark T64X -- False 927.02 Errors

927.02 is a 'cartridge fan stalled' error. Its likeliest cause is an open 10 ohm resistor, R30.^[1] Lexmark published a bulletin about this saying to replace the System PCA to solve the problem. Doing that certainly does solve the problem, but there's a cheaper way -- solder in a replacement resistor.

Here's a view of R30. It's near the upper front corner of the PCA.

R30 is at the centre of the photo. In the event of a 927.02 error, check R30 with an ohmmeter. It should read 10 ohms or very close to it. A very high reading is a certain indication that R30 is open.

There's no need to remove the defective surface-mount resistor, just solder a replacement conventional resistor in place across R30.

We didn't have any 10 ohm resistors on hand when I went to try this repair, so I had to use two 4.7 ohm resistors in series -- close enough. Here's a view of the completed repair after flux removal with flux solvent.

That board went back into a T644 with two add-on 500-sheet trays, and I ran quite a lot of paper through it with no recurrence of the error. All indications are that this is a sound, legitimate fix.

Soldering Technique

No special equipment is needed for this. I used an old Weller WTCPT soldering station with a TC201T iron and an 800° Fahrenheit tip, like so.

60/40 tin/lead solder works fine. There is one catch -- you have to have suitable liquid or paste flux^[2] so you can apply flux prior to applying heat/solder. Here's how it's done:

a) Cut and shape a resistor's leads A/R to fit in place at the ends of the existing surface- mount resistor.

b) Apply flux to the area of the solder joints.

c) Hold the prepared resistor in place.

d) Load a bit of solder onto the soldering iron's clean tip and apply the solder-bearing tip to one connection point. The flux acts as a very effective heat-transfer medium. It takes only about one, maybe two seconds for the solder to flow and produce the effect seen in the second photo above. Repeat for the remaining connection point and you're done.

It's nice, but not essential, to clean away the flux residue with flux solvent. The residue from proper electronic solder flux is quite benign and will do no harm.

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Notes:

[1] On the resistor it says "100". What that means is "10, with zero zeroes before the decimal point". By that notation, a 100 ohm resistor would be marked "101", 1,000 ohms "102" and so forth.

[2] I still have liquid flux left from my circuit board repair days. The stuff is still available, but it's sold by the gallon. It's Kester No. 1544, Kester P/N 63-0000-1544.

An alternative is Kester's 186 RMA Flux Pen, Kester P/N 83-1000-0186.

Don't use the common paste flux meant for soldering copper pipe. That stuff leaves a corrosive residue.

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Oki 590/1 -- Ribbon Drive

An Oki 591 is in the shop with an inoperative ribbon drive. The wire projection at the top of the drive spindle is sheared away. Apart from that, the mechanism is working fine. Here's a view of the ruined spindle.

A replacement ribbon drive gear case is P/N 51228501. We don't have one in stock, and the customer would likely squawk about the price anyway, so I'll try replacing just the spindle with one from a salvaged gear case.

The ribbon drive gear case on a 590/1 incorporates an auto gap-setting mechanism. This one appears to be working ok, so this should work out alright.

The gear case has four claws holding it to the carriage. Unlike the 320/1 Turbo, this gear case is not entangled with the carriage cable, so it's quite easy to remove it in one piece with the carriage in place in the printer.

Carefully separate the two halves of the gear case, and you get to here.

The ribbon drive spindle should be the only item to remain with the upper half.

With none of the gears askew or in disarray, it's a straightforward job to replace the ribbon drive spindle and snap the gear case back together.

You have to check printhead gap and parallelism on reassembly. The manual calls for a 0.014" gap at gap setting '2'. That seems too small a gap to me; I set these printers to 0.016" at gap setting '2'. To manually obtain a desired gap setting, turn the adjustment screw gently as you move the carriage -- that gets the big auto-gap wheel to jump an increment. Repeat as needed to get to position '2'. With the correct position selected, the gap and parallelism adjustment procedure is no different from that for the 320/1 Turbo.

Anyway, this repair went nicely. Fortunately, the machine overall is in good shape, and all it needed was the ribbon drive spindle and some cleaning up. More often than not, these things are basket cases when they arrive here -- in need of a thorough overhaul, or the short journey to the big bin out back.

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