HP Original Print Cartridges




Fusers and Maintenance Kits

We sell printers, toners and spares.   We aren't eager to sell fusers to people with 50.3 errors because it may not clear the fault. Check settings first. Look at the printer vents, are they clogged with dust?  




Power Distribution

The techy community get up to some peculiar things, one of our interests is power distribution.

The world is broadly divided into two main electrical power groups based on commercial and political decisions made in the late nineteenth and early twentieth century.

Japan, Taiwan, North America and some parts of South America use a voltage normally said to be 110 or perhaps 120 volts. This was inherited from Edison's early DC lighting system, which used 100 volts to light the carbon filament bulbs and had an extra ten volts to overcome losses in the cables. This was altered to use AC when the value of having transformers in the transmission system was realized. In the US the power supply is actually single phase 240 volts with a centre-tapped neutral giving two 120 volt supplies that can also provide 240 volts for heating.

Europe, the UK, Africa, Asia, Australia, New Zealand and most of South America use electric power said to be at 220 volts. Actually the UK and Australia used 240 volts but later agreed to "harmonise" with the rest of the world by reducing to 230 volts.

In practice we British didn't do anything, just agreed a standard that is 230 V +10% / -6% with that +10% allowing us to stay at 240 volts, drifting as high as 253 volts. However there is an allowance for the power supply to be out of range 5% of the time.

Looking at a power monitor every now and then just to see what is going on is not everyone's taste. However it is interesting to see power at 256 volts at 6:30am - 36 volts over the nominal rating.

Some UPS's actually monitor the power so it is possible to get a record of it; see here.

Because we British continue to use an unnecessarily high voltage, we use a bit more electricity than we need. We quite possibly suffer lower reliability with things like computer power supplies and LED lighting.

The effect on heating devices depends on details of their working. Kettles will boil more quickly with a higher voltage. Ovens will reach 200°C more quickly, but the thermostat will still cut the power as the temperature passes its setting point, then cycle around it.

For things like laser printer fusers whether a high voltage can take them out of range depends on software details. Does the DC controller check temperature every cycle in which case temperature would be very finely controlled, or every few seconds in which case it could rise too high. Firmware is closed source, so outsiders can't know, but it wouldn't be startling if the UK had more 50.3 errors.

power monitor

Reliable Remanufactured Cartridges

One of the merits of the P4014 against a new printer is the low cost of good re-manufactured cartridges.


At the moment we don't sell in the US, but we hope to soon

Error 50.3: HP P4014, P4015 & P4515 Printers.

top-right-photo P4014 series fuser

Laser printer fusers adhere toner powder to a page using a combination of heat and pressure. Error 50.3 suggests the fuser became too hot, which might be a failed fan, bad ventilation, bad power supply or wrong settings. The fuser may not be to blame. We can suggest one fault that might be the fuser: inadequate lubrication of the fuser sleeve.

Other fuser errors are:50.150.2 50.450.550.650.750.850.9

50.3: Fuser Error.

50.3 Fuser Error Warm Up Service or Fuser Error High Temperature. The fuser became hotter than expected.

The high temperature problems that give "50.3" might seem the converse of "50.2" low temperature but the two are rather different. Extension leads won't cause high voltage; nor will most possible failure modes in the fuser heater. High temperature could be because of power, ventilation or a failure in the control circuit. A defect in the fuser is possible, but not a certain diagnosis merely on the basis of a 50.3 message.

High fuser temperature could be caused by the electricity supply giving high voltages, and this is more common than generally thought. However, before jumping to the conclusion that the fuser has gone wrong - or the power supply is overwhelming the printer, some other checks will help. Some of these checks are not very easy, but could save time and money.

Quick Answers?

Wrong settings. A high fuser setting used on ordinary paper that isn't removing heat at the expected speed. An error message will be a help here as running the fuser too hot will shorten its life.

Bad lubrication. Inadequate high temperature lubrication in the fuser not transferring heat from the ceramic to the foil.

Blocked fan. Printer innards generally need to stay cool whilst the fuser is hot. Four fans cool the machine.

Working too hard so that heat builds up excessively (we'd be a bit surprised at this).

Thermistor failure would obviously give a wrong temperature.

Control breakdown, but we would expect that to get to the point where the thermal cut-out operates.

Bad Voltage. Too high a voltage causing the fuser heater to overshoot.

Bad frequency or power factor. Fuser power switching circuits require something between 45 and 65 hertz and sine wave to work correctly.

vertical creasing

Overheated Fuser

Before looking at the cause of a 50.3 error it might be an idea to see why it matters.   Signs of an over-hot fuser before an error happens are:

  • Creases vertically in the paper. Paper creasing usually happens when the fuser is hot and / or the paper is somewhat damp. Paper always contains some water - it is a hygroscopic material and will pick up moisture from the atmosphere if is not hermetically sealed in a pack. Very dry paper may not work in a laser printer anyway, the electrostatic transfer characteristics would be odd. Paper comes into the fuser cold and is suddenly hit with blazing heat, it expands and softens as steam is driven off but not at all evenly as it is in the tight grip of the pressure roller. The result can be one or two somewhat irregular creases down the page. Other signs of the same problem is that paper will curl excessively in the output tray, sometimes rolling up into a cylinder along its length. Obviously paper in this condition won't pass through a duplexer reliably.
  • offsetting is another possibility. The toner is too hot, melts and sticks to the hot surface but the paper does manage to separate from the fuser. Some toner is left on the fuser, travels round and makes echoes or ghosts of the print down the page. This is known as offsetting; the ghost print is at intervals of 94 mm which is the circumference of the fuser sleeve. If you take the fuser out and look at the sleeve it is coated with a patina of baked toner. vertical creasing
  • paper wraps into the fuser. The toner gets too hot and tacky, the page cover is too high and the paper fails to separate from the heated surface. It sticks to the hot surface of the sleeve and disappears into the fuser. The printer should go to a 13.xx error as the page never emerges. This can be difficult to spot as the paper wrapped around a fuser looks just like a oddly coloured roller (yellowed paper instead of brown fuser-sleeve). It is also difficult to fix without dismantling the fuser. The trailing edge of the paper may be visible and it can be gently teased out and peeled away.

These things can happen without the printer actually going to error, although the last problem is very likely to precipitate a "50.3". With a blanket around it the fuser will get too hot in the middle, too cool on the outside.

fuser

Outline of the Works

Laser printers use pulses of high power to heat the fuser. The fuser forces soft plastic toner powder into the surface of a medium such as paper giving a tough, wear resistant finish to a page. To do that the fuser raises the surface of the page momentarily near the melting point of the toner. At the same time a pressure roller drives the toner into the pores of the medium. The toner powder used in the LaserJet P4014 series printers is a mix of polyester and iron oxide specially chosen for its low melting point because that improves energy efficiency. HP say (on the MSDS) that the specific polyester used is a trade secret. A bit more information on toner behaviour is available under the CC364A cartridge heading.

thermostatic control system

The fuser used in the P4014 series(further information here) is a design invented by Canon and HP that uses a ceramic bar heater wrapped in a rotatable sleeve of non-stick Teflon like material on a metal film to prevent smudging. The heater is a strip of ceramic with a pair of thick-film metal and carbon like traces on it acting as heaters. The heaters are quite powerful; in action the printers draw just under a kilowatt of power and almost all of that goes towards fusing. If the heaters were not in contact with the sleeve and continually cooled by a flow of paper we suspect they could light up yellow and burn out. (We haven't tried it because we don't have any heaters to waste on entertainment).

The heater is not normally in danger of burning out because it is protected in two ways.

overheating cut-out

Thermal Cutout. the metal button pushes on the heater tracks. Overtemperature breaks the fuser circuit

The normal thermostatic control circuit built around a thermistor on the back of the heater. The thermistor feeds temperature readings to the DC-Controller, a microprocessor responsible for print-engine actions in general. The DC controller is told what temperature to reach by commands from the control panel, or from the formatter (which gets them over the network from the driver in the user's computer). The DC-Controller doesn't actually have the clunky components needed to control power itself, they are on the power supply board. Control of the fuser is therefore spread across the fuser itself, the DC-Controller and the power supply board. In addition there is a thermistor on one of the fans acting as an environmental temperature sensor and this lets the DC controller estimate how much power will be needed to raise the fuser to working temperature.

Fuser control is rather complicated and there is a failure point. When a triac goes faulty after a power surge they have a bit of a habit of failing closed-circuit - rather than turn off they go full-on. The fuser carries a thermal cutout to prevent this causing a fire. If the thermal cutout is raised above its rated temperature it interrupts the fuser power circuit, preventing a fire hazard.

fuser-circuit

What Could Go Wrong?

Ventilation is a possible cause of problems. An excessive temperature might suggest a ventilation problem or fan failure. The P4014 series designs use no fewer than four fans, although they aren't all necessarily at full power unless the printer has done a lot of work (the printers are sometimes criticised as noisy). It is widely suggested that blocking the fan vents on the side of the printer can trigger 50.3 errors.

Ventilation issues are a slight puzzle. If the fuser innards are becoming too hot why does the DC controller feedback circuit not reduce power to the fuser until the flow of paper (or air from the four fans) cools it down?

thermistor

Main and sub-thermistors in the LJ-P4014 fuser. These are in the nip-point between the sleeve and roller, normally covered by the metal sleeve.

dirty fan

Laser printer fans can get really filthy. This one did a few years service in a shipyard and still functioned but it is easy to see how they could get completely clogged. Dust build-up inside a printer can cause strange behaviour.

Heavy work might cause overheating. It may be possible to trigger "50.3" by working the printer continually, or on heavy materials like card-stock which require the fuser temperature turned up. Some printers slow down in circumstances where they have been pushed to overheating. We aren't clear that the P4014 series do that although it does slow down for some materials from tray 1. One of the errors in early versions of the firmware was to switch to slow-print jobs from tray 1 when there was a fuser problem. Was this apparent software error actually a feature - that it could print at all with a partly dud fuser?

thermistor

The thermistor circuit could fail. Thermistors work in the temperature range they are rated for - which in this case runs quite high (more information here). We don't actually know what temperature the core of the fuser operates at, we see other sites giving figures like 350 centigrade but we doubt that and also think it will depend on what point is measured - the actual heater element, the sleeve adjacent to the heater or the paper in the nip-point between heater, sleeve and pressure roller. The heater will be somewhat hotter than the paper passing under it, as it acts as a reservoir. Paper trapped in a fuser discolours but doesn't usually char much. Thermistors do operate hot and they can fail - although they seem to be one of the most reliable electronic components. It is fairly easy to test a thermistor- they are simply resistances that vary with temperature.

Control breakdown is the worst possibility because it could be spread across several positions. The DC controller and environment sensor thermistor could be implicated. The most likely point of failure is on the power-supply board. If so:

  • It is going to be difficult to diagnose, the power supply is deep inside the machine and not easy to work on because it deals with mains power and makes the high voltage for the cartridge and transfer rollers. It will be quite difficult to test out of circuit. There is no circuit diagram. high voltage
  • It could be expensive to fix. New "High Voltage Power Supplies" from HP are expensive - although we can probably source "refurbs" (ie clean working pulls) from decommissioned machines.
  • It will be difficult to fix anyway. The board is in a difficult position in the LaserJet P4014 series - half the printer has to be dismantled to exchange it.

Control breakdown is difficult. We would expect damaged triac-type circuits to go open circuit (fuser won't heat) or closed circuit - fuser gets too hot and goes initially to 50.3 then perhaps 50.6. However we can't see any circuit to monitor the thermal cutout, the circuit diagram doesn't show one and the fuser hasn't got one.

Rogue mains power seems a likely culprit for "50.3" errors in our opinion. The fuser got too hot more quickly than the DC-controller firmware expected. Despite all the electronics in the printer, the fuser is actually a heater connected quite directly to the mains. If the mains voltage is 10 percent higher than it nominally ought to be, then current goes up 10 percent as well and so the power output of the fuser is 21 percent higher than expected (presuming the resistance of the heater doesn't change). That is quite a significant effect.

UPSs are for computers, NOT laser printers. In principle it might sound as though laser printers could benefit from the sort of power regulation provided by a UPS. However that is probably the worst thing to do unless you have the budget for a very hefty UPS. In principle the UPS should give a stable output at the printer's design voltage. In practice a P4014 series device is a huge load of about 840 watts average when it is printing and somewhat over a kilowatt when the fuser is operating. It would need a supply rated at 3 kilowatts or more (about 4KVA) to guarantee a good supply to most laser printers. (The fuser is a resistive load, but it has a triac switching circuit and the effect of that is unknown. If too much load is placed on a UPS or inverter the frequency, power-factor and voltage will all be out of kilter and the result could be malfunctioning of the fuser control circuits. For instance, power switching semiconductors are generally intended to operate at the zero-volts point of the AC power cycle but if the power factor is bad that is not the zero current point and the switch could be destroyed. If you must have printing protected by a UPS choose an inkjet, they don't have the high power demand of a fuser.

50.3 problems seem likely to be printers being fed too high a voltage or an odd power-factor. Metering power supplies is a bit difficult and could be dangerous, although it only needs a multimeter set for AC volts. Many UPS's will report the line voltage, so a report from one of those near the printer can help (no, the printer doesn't need plugging into it, the UPS and printer just have to be on the same circuit). Perhaps it is best to look at simpler solutions first.

Diagnosis & Repair

50.3 is quite likely to be fixed by unplugging the printer, leaving it to cool down for half an hour then trying again. DO NOT merely turn the printer off and on again, there is a risk that a second dose of power will push the fuser to the point where the fuser cutout operates or actual damage occurs. Cycle the printer power a couple of times over an hour or so before concluding that a new fuser or any other action is needed.

The LaserJet P4014, P4015 and P4515 have no fewer than four fans to give the machine airflow. Fan failure should raise a "57.xx" error of course, but it probably is possible to have a fan that does turn sufficiently to not give an error. Make sure all the fans are fairly clean and spin freely.

Fans are no use if users block the vents with ledgers, catalogues and other desktop clutter. Allow about 150mm clearance on every side. Printers should really occupy their own table as they shouldn't be too close to users.

If the problem persists another point to check might be the printer driver fuser setting. The P4014 has four fuser settings (for each media type) the idea being that the user can select the one with best results. It is possible that firmware might be confused by particular settings. Most HP printers have the fuser temperature settings in a "PRINT QUALITY" menu under "FUSER MODES" and can set the level to Low, Normal, High1 and High". This printer series (P4014 etc) seems to have Light1, Light 2, Normal and Heavy but that might be firmware dependent. Generally a higher setting will work better on heavier media like letterheads and envelopes - at the possible cost of a shorter life for the fuser. If there are frequent 50.3 errors work from the basis of the default settings.

thermistor

A warm up problem might be caused by the environment thermistor. If the printer has been moved from a cold to a hot room (or from a warm place to a cool one) then the environment thermistor will be wrong and the fuser warm-up timing will be out as well.

Certain combinations of media and settings may be capable of giving the 50.3 error during a print run. The fuser shouldn't be run too hot - it is bad for the pressure roller rubber and the bearings if nothing else so if it does go to error that may be a blessing in disguise.

Somewhere in their list of instructions on the "50.3" error everyone says something along the lines of "remove, inspect and reseat the fuser". There is no harm in it. It is possible that the thermistor contacts were tarnished - and you might find a label or other foreign object stuck around the fuser sleeve preventing it radiating heat properly.

If the fuser sleeve does not rotate properly then if media were to arrive print will smear. However the fuser should be moving and at temperature before the print media arrives so if the film is not carrying heat away presumably the 50.3 error could happen.

Ultimately you may need a multimeter to solve "50.3" problems. First to test the fuser, try metering the heater circuit and thermistor to find out if it is good.

You may need to test the mains power (line voltage). Since exposed meter probes could deliver a fatal electric shock this should be left for an experienced technician if you have the slightest doubt about your own abilities. Another alternative is a plug-in energy meter, which will often display the voltage and many of the better UPSs will give a read-out of current line voltage as well

We cannot definitely say error 50.3 is NOT a bad fuser - but since fusers are expensive it would be wise to eliminate other possibilities first. Multimeters cost about £10 and are handy for anyone with technical interests. Fusers cost about £180 delivered. If you have a "50.3" - check the other things before buying a fuser.

Web Research

I tried querying Google with P4015 "50.3 FUSER ERROR" in quotes and got About 3,380 results suggesting some minor interest in the topic.

  • printerrepairsupport Brief article, to the point so far as it goes. I'd want to do more checks before concluding a fuser needs replacing on the grounds of a 50.3 error.
  • thelaserguys Generic page on "50 Service Errors" I think this site was once good and has been allowed to drift out of date, every printer mentioned on this page is near-obsolete. Even if it were up to date there isn't much information on the topic.
  • HP_forums seem to specialise in one-question, one-answer stuff. Not very informative but recommends checking the input voltage readings.
  • fixyourownprinter Forum thread right on the point but doesn't arrive at a fix.
  • twitter for FW printer repair. No use for my purposes
  • fortwayneprinterrepair
  • fortwayneprinterrepair puffing his own article
  • depot-america For old printers and scraped from the service manual.
  • fixya The usual mixed bag of irrelevances with one mention of 50.3 and no solution. If Fixya didn't exist would it prove necessary to reinvent it.
  • putangas fortwayneprinterrepair puffing his stuff.
  • rhinotek somewhat dated list

Whilst the articles generally covered the same ground I didn't feel they made any headway into how a fuser could get over-temperature without some glitch in the feedback loop allowing it to do that.