I'd be interested to know if I'm alone here but over the past year I've experienced a large number of problems with the HP88 printheads in the K550 printer.. Given that this printhead is shared with other later models such as the K5400 and L7000 MFD series of printers from HP it's getting to be something of a concern.

When I discovered that 3 separate black and yellow print head units had all failed with varying degrees of problems I realised this wasn't "normal" and did some digging to find that there is a known issue with these print heads when shipped with a lot of the K550's.

Now that's all well and good but I've started seeing printheads dying that don't fit this description and even one that was a Cyan/Magenta head.

Symptoms I've experienced so far include:
- Black fades out or fades in when first printing.. becomes more severe over time.
- Black disappears completely (Y, C, M all continue to print normally).. Can revive with a LOT of cleaning routines but soon disappears in 24 hours.
- Banding of the other colour appear in areas of one colour.. ie: (yellow stripes in black, black stripes in yellow, cyan in magenta, etc.. )


I couldn't completely rule out the issue being related to CIS installation or ink pressure issues but it does seem that these print heads aren't overly well spec'd for the job they do and certainly the diagnostics system in the K550 just doesn't spot problems at all, as all heads have been reported as "good" or "fair" even when completely fubar.


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Printers: (Canon) MP500/830, MX700, iP4000/4200/4300/4500/5200, iX4000(A3) (Epson) C84/86, D88, CX6600, R285/800/1900 (HP) K550, K850, K5400, L7680

Hi Martin,

I felt a bit better after reading your post. I have a relatively new HP8600 that uses the 88 cartridges and after just 1000 pages, the black has become so erratic that it is just so frustrating! I can soak the head in hot water for a few moments and replace it and get a couple more pages printed before it fades away again. I am using a refillable cartridge but don't think thats the problem. Time to replace but hope this is not a recurring problem. Do you have any updates or thoughts (your post is a year old now!) For the cost of 2 new printheads you are well on your way to a new printer!

Thanks
Jon

Just as an update and to provide a little more intel as I've forgotten to share it on here.

There's definitely a temperature/humidity aspect to the printhead and ink.

I've spent considerable time testing inks from OCP and Image Specialists (two very good quality ink manufactures) as well as using the genuine OEM's and it's pretty obvious that the problem affects them all when the room gets to around 22 or so degrees of "dry" heat.

By that I mean, central heating, air conditioned, etc... Strangely the problem was not as bad during the summer, even in an attic being heated up to around 28+ by the sun.. The fact that the air was being circulated with fresh air (Oh heck did I have the windows open! ) helped it seems and it's not a dry heat here.


I have one school that heats up with 30+ computers pumping out dry heat and it's made worse by the air conditioning unit trying to remove that but drying the air even further. Net result was always a bunged up printhead, often after less than a week of printing...

I've since moved to using a dyebase ink which does produce a bleed effect making it useless for quality photos but given that the printer is anything but a photo printer that's no major loss.



All of this is by no means scientific but it does point to the printhead being badly designed for pigment inks and the whole 40 degrees working temp thing on HP's spec' is just a joke I haven't got yet


_________________
Printers: (Canon) MP500/830, MX700, iP4000/4200/4300/4500/5200, iX4000(A3) (Epson) C84/86, D88, CX6600, R285/800/1900 (HP) K550, K850, K5400, L7680

Having had a few of these printers up and running now for over a year I'm now in a position to provide a bit more intel on the HP88 and some solutions I've discovered through experimentation, observation and pure ruddy luck!


1. The environment side of things is definitely a prime cause.
The printers living in cool, corridor conditions are only now showing slight signs of clogging whereas the printers that have been in air conditioned rooms or in classrooms with lots of heating have been showing much more prevelance to clogging and banding.


2. The printers own Printhead cleaning...
...whilst very effective for the dyebase printheads is not overly so with the pigment black head. Instead it tends to clear up some but not all clogging issues and clogs just gets worse over time giving the distinct impression of a dead head.


3. Manual printhead cleaning:
When I first tackled this a year back, I tried a method that has succeeded admirably with Epson and Canon printheads. In essence the approach involves a solvent soaked pad on which the printhead is rested. This should allow the solvent to wick up into the head and breakdown the clog. The actual solvent itself is either an ammoniated solution or a dilute base solution used in the inks themselves.

Unfortunately this approach failed abysmally with the printhead output becoming more and more banded and eventually failing completely after a very short time.

Having examined this further I've come to the conclusion that this is largely caused by the printhead design, in that the system is more or less a self-contained printhead/cartridge which pulls air bubbles into the head as the clog breaks down. My guess (and it is just a guess) is that the pad itself draws the ink out of the printhead thus propogating or increasing the draw of air in to replace it.

Unfortunately because of the design of the HP88 printheads it's nigh on impossible to re-prime them (not that I've tried particularly hard).

3b. Cleaning that works?
However.. I have found a solution which has worked once and which I will be keeping an eye on (ie: trying again) over the next few months.

Instead of putting the solvent on a pad, I've found that one method that works is to place the HP88 printhead upside down on a flat surface (nozzle jets facing up) and then gently drop small droplets of cleaning solution (ammoniated solution/ ink base) on the printhead nozzle surface using a syringe or eye dropper. It only requires a small amount of solution but this goes to work on any clogged ink fairly quickly.

At no point should any absorbant pad or material be used to draw off the excess but the printhead should remain "wet". The printhead then gets replaced and a priming sequence should usually run.

I've done this successfully with an HP88 K/Y printhead out of a K5400 which had a clog starting. The solution was allowed to sit on the printhead nozzle area for about 30 seconds and then it went back in without wiping anything off.. Basically I let the printer handle the cleaning part and it seems to have done the trick.


4. Dyebase Black vs' Pigment Black
Given the fact that the dyebase CMY inks still work perfectly in the environments that the pigment black clogs quickly in, the use of a dyebase alternative is definitely worth considering if your printers local environment fits the bill. The advantages are that the printer doesn't tend to clog but the downside is of course that you get some ink bleed in high coverage printouts and the black is not quite as a sharp.

I'm playing with a dye/pigment mix using ink from the same manufacturer so the base solution should be the same and seeing how that works out. So far it's early days but it may be worth considering to get the best of both worlds... It's very much a YMMV type deal though so proceed with caution.



Hope that update helps and if anyone else tries the cleaning routine suggested in 3b I'd be interested to hear if you find it's a viable approach too.


_________________
Printers: (Canon) MP500/830, MX700, iP4000/4200/4300/4500/5200, iX4000(A3) (Epson) C84/86, D88, CX6600, R285/800/1900 (HP) K550, K850, K5400, L7680

joncroke wrote:

Hi Martin,

I felt a bit better after reading your post. I have a relatively new HP8600 that uses the 88 cartridges and after just 1000 pages, the black has become so erratic that it is just so frustrating! I can soak the head in hot water for a few moments and replace it and get a couple more pages printed before it fades away again. I am using a refillable cartridge but don't think thats the problem. Time to replace but hope this is not a recurring problem. Do you have any updates or thoughts (your post is a year old now!) For the cost of 2 new printheads you are well on your way to a new printer!

Thanks
Jon

yeah now i know, thanks for giving me some idea


Mod Note: spam? urls removed..

I've 2 K550 and I'm about to print 10k A4 colour pages per month. I'm aware of that printhead problem but since those printers are so cheap I hope it compensates all the pain.
(I've chosen specifically that printer because it's one of the most efficient of the market, this is, less ink per page (because I'll be filling refillable cartridges (not a CISS because large refillable cartridges have the same capacity as a CISS tank))) hence super cheap.

Anyway I've tried MANY MANY times to get an answer from HP to tell me how much time or how many pages a printhead would last. I never got an answer.
BUT they told me several times that printheads have a 6month guarantee from the date of purchase! So I can print whatever I want because they will always replace. Of course printheads don't last 50k pages. Not a problem since they won't known how much I've printed =)

I'm expecting lot's of problems regarding printheads. but that's not all. K550's are known for having paper handling problems. Though a duplexer and a paper tray can minimize a lot those problems.

Hi, this is my first post.

I am just about to give up on trying to get a CISS working for my officejet 7000 A3 (using a HP 6500 CISS as same cartrdige). I will get some high capacity original carts then refill.

So I am now planning on getting a K8600 which I intent on printing 8000 sides of A3 a month (or equivalent of 16000 sides of A4). I know I will need at least 2 printers, and will aim to have an array of about 5 after I get up and running. Due to the CISS friendliness of the K8600 I'm hoping its going to work okay, and that as i'll be printing a high volume I will get close to the 42000 pages stated for the HP88 print heads, possibly more. I intend using pigmented black ink as I will be able to control the humidity and temperature of the print room to be ideal for the print heads.

I know martin has mentioned air in the printheads, has anyone tried putting the head into a vacuum chamber and sucking the air out, i'm talking mechanical rather than manual sucking

Adrian.

Just to update on this as it's been quite a while now and I've had a chance to see how things last over a longer period of time...

1. Pigment inks in HP88 printers have not changed and if anything the decision by HP to go with completely pigment orientated printers in later models of the Officejet makes me wonder what they are drinking... (Printer driver "fun" not withstanding)

2. After a lot of experimentation I've found that the Epson Dyebase Black ink provides a perfect replacement for the original HP88 black with a very good match. After sitting in a printhead for 2 weeks (in a baking hot room @ 30+ degrees C) while I sorted a problem with a CIS kit, it also didn't clog.


As to sucking ink out... I haven't tried it to be honest... Chances are it would damage the nozzles if you weren't careful.


_________________
Printers: (Canon) MP500/830, MX700, iP4000/4200/4300/4500/5200, iX4000(A3) (Epson) C84/86, D88, CX6600, R285/800/1900 (HP) K550, K850, K5400, L7680

I have read the posts. I believe that useful info can be added.
1. It is likely airconditioning will dry out the print head surface. With a CISS and regular printing each day this will not usually be a problem.
2. The best method to disolve dried ink in the jets. Place some Windex about 4mm deep in a small dish that will allow the print head jets to be immersed. Soak for half an hour, then use an up and down motion to cause hydraulic pressure to flush the jets, the jet surface must go down to the dish surface to maximise the flushing.
3. If step 2 works but the head lasts only for about a day then more serious cleaning is required by dismantling and cleaning the inside of the cartridge (most often required for the black jets) see the video on this link: http://vimeo.com/35345649
Use Windex as the cleaner at the appropraite stage. Whilst using the Windex the ink /fluid flow through the jets should be obvious and free flowing for a good result.
Please understand the last phase of blowing air into the head. This is to expand the internal bladder to remove excess ink, the bag then collapses to create a small negative internal pressure to stop the ink dripping freely. Several blowing sessions are required.
The video gives some good info BUT. a) It is best to remove the chip before exposing it to the water and replace with double sided tape when cleaning is complete. b) Use a syringe to also flush out the input ports with Windex before re-assembling C) I finally flush the cartridge with distilled water to remove particulates that may be present in tap water (an option because there is an internal filter for each set of jet nozzles)
4. It has been stated that air in the jets is a problem. If the head is understood this cannot happen unless the head is emptied of ink, all air will be at the top of the cartridge. Placing the cartridge upside down will bring air to the jets.
5. IMPORTANT. If the ink is not being correctly transported to the cartridge it will run out of ink and the jets can be ruined. The HP supplied cartridges have a bladder pump to ensure ink supply, clearly there is a reason for this additional complication. Some CISS systems and refillable cartridges do not have the bladder pumps in the cartridges, get cartridges with bladder pumps and make sure the pump is bled and working correctly. To bleed first fill the cartridge then attach a 1 mm diameter ink filling needle to a syringe. Position the cartridge so that the output port is uppermost and then insert the needle into the port and draw back on the syringe drawing out air and ink (3ml or more). The ink can be returned to the cartridge CISS. The pump can be tested by inserting the same needle but with the syringe plunger removed, depress and release the visible bladder a number of times, ink should be pumped into the syringe.

Evidence of insufficient ink in the print head. I had a head that would operate for a short time on the black jets after the Windex dish clean and I suspected that there was lack of ink. Upon opening the cartridge no ink could be seen above the internal filter (lack of ink). When this happens the whole ink supply line needs to be checked out, including the cartridge pump action.

I am using a Rihac CISS on my K5300 printer. I have been very pleased with the design and performance of the Rihac systems and inks having used them for many years. They have been very successful with Canon iP series printers. I see posts that state Canon printers are difficult to use with CISS , well that has not been my experience with Rihac.

Hope this will prove helpful.

PLEASE HELP ME This is an issue which has occurred a few times,now and I am in the middle of trying to complete a postgraduate research thesis via distance learning and its causing huge problems (I live in a small town, there is nowhere I can go to get things printed for me, and I cannot pay rent at the moment let alone afford to go travelling off on the bus to different towns two or three times a day!)
I have an HP Officejet Pro L7680 printer, and while the cyan/ magenta printhead lasts like a dream for years on end with masses of printing, the black/ yellow one fails usually after printing about 100 pages or so. I have checked ink cartridge levels, reset the printer, cleaned print heads, calibrated line feed, everything you can think of, and it has no effect.

The printer is in a dry, dust free area, normal room temp, not near any heaters or anything. We do not have airconditioning.
Obviously I cannot afford to replace a print head every 100 pages or so!
All advice as to what to try to at least keep the printer limping through the summer is desparately needed.