Epson Printhead Kit 1497824 .

Epson Head Kit 1497824 is a replacement printhead, ribbon mask and ribbon mask holder for the LQ-590 and LQ-2090 printers. The service manual gives the part number as 1279490 - that has been superseded.

Part 1497824 should be marked available in the catalog, although it may be order on request 5-7 day delivery. If it is not marked available email and ask.  

The 1497824 /1279490 Head Kit fits the LQ-590 and LQ-2090. So far as we know it is not used elsewhere.

The printhead is a 24 pin device made inside an aluminium casting that acts as a heatsink. The head is held in place by a screw on either side. Dealing with problems sometimes means unscrewing the head to examine the pins. Close examination of the nose will show the pins are in two rows of 12, slightly offset from one another. The pins are set in a white "jewel" which maintains their position. A matrix 24 high is enough to give well formed characters - at least as good on the average computer monitor.When screwing the head back in tighten it but do not damage the screw head or the threads in the carriage. They are not easily replaceable. Use the correct screwdriver and do not force it.

In operation the pins strike the ribbon, driving ink off it and onto the paper. The movement in a typical dot-matrix pin is quite short-pitched, a millimetre or so with 2 millimetres maximum. Ideally the pin should move the right distance, which is set by the platen-gap. If the printhead is too:

• close to the paper the ribbon will be scuffed against the page. The energy in the pins will be wrong and print will be uneven. Printing usually sounds rather muffled.
• far from the paper the pins won't reach at first, then there will be faint, uneven print with a risk that on recoil they will fall out of the jewel. Printing usually sounds exceptionally harsh.

After some millions of characters work the pin tips of a printhead begin to wear away. This is usually most evident on the bottom row of upper case characters because that pin fires on almost every character. The lowest four pins used to print descenders on lower-case tend to remain quite prominent because they are less used. When the pins are different lengths print dots are uneven, wear on the ribbon becomes excessive, and adjust the platen gap becomes an uneasy compromise with smeared text likely.

A common problem with dot matrix heads is that some pins become so worn or recoil so sharply they fall inside the printhead jewel. This can sometimes be fixed on a 9 pin printhead but is too difficult with a 24 pin head. The problem is visible, careful examination of the head will show a couple of black holes where the pins should be. A sample printout has corresponding missing dots.

A less disruptive problem is that the print-jewel holes which should be circular wears into elliptical shapes. The pins then fire at random angles so print-characters are malformed.

Malformed characters can be the fault of the carriage cable or the printer control board rather than the printhead itself. The carriage cables take all 24 signals and their returns between the driver circuits on the control board and the printhead moving on the carriage. There are a couple of connectors for things like overtemperature thermistors as well. The cable is a pair of "FFCs" Flat, Flexible Cables which have copper strips embedded in a plastic sheath. After many hours flexing back and forth the copper gets metal fatigue and breaks down, the connection become erratic and it may burn a hole in the plastic. If the metal layer inside the cable short-circuits against the chassis of the printer that can damage the drive circuits so the printer should not be allowed to run in such a state.

Printheads in this class are generally considered consumable rather than repairable.

Dot-matrix printers usually make faults self-evident, one of the print pins goes missing. With a 24-pin dot matrix head this is not always completely evident, there is a white streak through the characters but to most people with normal sight it isn't self evident that a pin has failed because the visual disruption isn't entirely clear. Short-sighted people can often spot the problem more easily.

Carriage Cable

The carriage cable for the LQ-2090 is 2085778. The cable for the LQ-590 (Not illustrated ) is 2085777.

A split in a printhead cable can give faults that look similar to those in the printhead itself.   As already suggested, the cable carries the drive currents for the solenoids in the printhead. Metal fatigue breaking the tracks cuts the link between the diver circuit and the pin. A dead driver circuit could also cause a pin to stop moving. In most cases there will be a visible problem, a split in the cable, a pin dropped out of the printhead. If there is no visible sign, the ways to distinguish the faulty components are either swapping parts (which could involve buying more than one part) or prolonged attention with a multimeter.

Epson Information

Epson do not seem to make any information available online for the replacement head kit 1497824.

Icecat says the EAN/UPC code is 5711045148620 but has no further information. There has been 24 product views in two years suggesting a low level of interest.

The number gives in Epson's spares list is 1279490, that part number changed to 1497824.

This printhead is only used in the LQ-590 and LQ-2090

Web Research

A Google Query on 1497824 (in quotes")

suggested a few dozen vendors but gave no further information.

Fitting the Printhead

The printhead is fairly easy to replace. Remove the two screws, (note that magnetic fields in the vicinity of printheads can lead to them behaving oddly). You will probably need to remove the printhead to examine it and determine whether replacement is necessary or some other problem is the issue. Clean the front of the head with a dry lint-free tissue to examine the pins themselves.

If the head does show worn pins then detach the old one from its cables - mark the cable positions if there is the least chance of getting them the wrong way round - the folds act as something of a guide.

The Epson head kit is usually supplied with a new ribbon shield holder and the small metal shield. The shield can be replaced if necessary, they are available as separate items.

In principle refurbished heads may be available. Epson's price for a new head seems reasonable, so we are not offering them at this time. They may not come with the shield.

Supply Situation

Epson will be the sole supplier of new printheads like this. At present they are available in the UK on a lead time of about 5-7 days.

For some reason Epson have taken to asking the serial number of printers before they will supply new printheads.

There is another possible source of supply in refurbished printheads. Refurbishing involves putting new pins, print jewel and anti-residual strips in the head and possibly rewinding any solenoid coils that are heat damaged. Flight-timing is then readjusted. At one time it was common practice and there are still people who can do the job. With these heads the Epson price and availability seems reasonable at present, so there is no need to go to those measures.

One of the UK distributors we deal with regularly can get these parts on a 5-7 day lead time. We also know an alternative distributor can get the parts but does not regularly list them. Epson favours a UK distributor who are unable to provide regular price lists, so whilst we know of them and can get stock that way we can't include them in our online catalog at this time. (We try to offer parts only if we definitely can get them).

This part should be marked available in the catalog, if not email and ask.