Why you should always rule out consumables first

[Kiran Otter]

This post mainly has to do with HP Designjet printers, but it probably holds true for any printer.

I keep telling folks to always rule out consumables (ink, printheads, media) before replacing parts in a printer. I recently drove over 2 hours to look at an HP Designjet 800 that wasn't printing. It would go through the motions, the carriage would travel back and forth, the paper would advance, but not a dot was put on the paper. I also discovered that if you tried to do the printhead alignment, it would get to just before it should start printing the alignment pattern, and just hang.

Naturally at first, I thought how could all 4 printheads be bad at the same time? That just doesn't happen. So I began to think I would have to come back (remember this printer is 2 hours away) with a carriage assembly, a trailing cable, and to be safe, a new electronics module. I wasn't happy about this.

I took the printheads out, made sure all the contacts were clean and not damaged, and the printer actually rejected the cyan print head at first, but after another reseat, it was OK. Still the printer would hang as it began the alignment process. I thought, if it's seeing me removing the printheads, what could be wrong with the carriage, trailing cable or emod? It's doing everything but printing.

The customer did have a full stock of inks and print heads, and remembering my own rule of 'rule out the consumables', I started replacing the inks, and then the printheads one by one. I replaced the cyan print head, to no avail. Then I replaced the magenta printhead, and the printer started printing. The other two printheads (black and yellow) were working perfectly at that point.

Needless to say I was very happy I didn't go down the path of replacing parts when it was a $49 printhead.

Yesterday I had a Z6100 that has a odd ghosting issue, like the cyan and black printheads are printing when they shouldn't be. The customer recently replaced the magenta/yellow heads (there's 2 for each pair of inks) and that was when the problem started. Unfortunately they threw out the old printheads and didn't have another, so after cleaning and making sure it wasn't a contamination issue, I told them to get another magenta/yellow head and try replacing the two in-turn to rule them out as the problem. Hopefully it's just one and not both. Why would the magenta/yellow cause the black/cyan head(s) misfire? All of the printheads are in a matrix, and it's not uncommon for one printhead to make it's neighbor misbehave. This also holds true for the ink cartridges.

I also recently had a 4520 that the customer claimed needed service, because the ink wasn't drying on the media they were using. It turned out that they went from using the Everyday Instant-Dry Photo Gloss media, to the Universal Photo Gloss, which is not instant-dry and apparently takes days to actually dry. Fortunately I was able to solve this via email without a site visit.

So always rule out the consumables!

Kiran

[Lance15]

I'd also like to add to not trust aftermarket parts. Customer input a call for a Designjet 5000ps. Said the belt and trailey cables needed to be replaced and they have parts onsite. After asking what prompted them to order the parts they did, I setup service this past Monday. Got down there, tore the plotter apart, quickly put the belt on the carriage (I did notice it was odd....). Did my best to install these aftermarket cables (JUST cables. no new clip to make sure the cables are spaced correctly or at the right length). Went back to the belt and after running it through my fingers, I noticed there was no "flip" in the belt. Flip meaning the toothed side was all on one side and flat (yes, flat, no grooves) were all on the other side. There was no way this belt was going to work! It just wasn't made right.

[Kiran Otter]

Yeah, they got it off ebay probably, from China. Some come with a new idler pully/wheel that is smooth (vs the stock one with the grooves) to compensate for the belt not being made right.

Last time I used one of those belts in a 500 (because a customer bought the belt, and against my recommendation) the belt lasted about 3 months. Then he had to pay me to come replace it a second time.

Same thing goes for fake ink/refillable ink cartridges.

Kiran

[KenB]

Yeah, they got it off ebay probably, from China. Some come with a new idler pully/wheel that is smooth (vs the stock one with the grooves) to compensate for the belt not being made right.

Last time I used one of those belts in a 500 (because a customer bought the belt, and against my recommendation) the belt lasted about 3 months. Then he had to pay me to come replace it a second time.

Same thing goes for fake ink/refillable ink cartridges.

Kiran

Bogus competitive supplies are the bane of our industry.

I actually had refilled Canon laser cartridges damage more than a few fax machines years ago.

The vendor was marketing the printer version of the cartridge to fit the Fax L700 series.

The correct version had 2 indents in the cartridge body for the toner sensor. The printer version had the windows, but they were not recessed like the fax version. (It was for the LBP4 model printer.)

The first time the customer put the bogus cartilage in, it would fit OK, until they closed the door. Once they did, it broke the toner sensor assembly.

As I recall, it was almost a $300 service call to replace the sensor. The part itself wasn't too expensive, but it involved a bunch of labor.

I must have changed at least a dozen or so of the little suckers.

[theengel]

Look, I started using those Chinese belts about a year ago. I did so because I had gotten several bad HP belts for the 500. The belts were slipping inside the carriage. I even took the carriage off, turned it upside down to make sure everything was in there correctly, and with just a little bit of tension, the belt would slip back and forth. The first time, I didn't have another belt with me, and the customer was in need, so I ended up putting a dab of superglue to hold it in place. That worked, but it's gonna be a b$$h to change that thing in a couple years.

Anyway, I started using the cheap Chinese belts, and I have yet to have a problem. Of course, I haven't used the cheap belts on anything that does high volume. But right now, I have a higher fail rate for OEM belts.

Speaking of printheads, do you guys pull printheads out and wipe them? I'm talking about those instances where the customer failed to call, let the machine sit for a month, and now has a bunch of nozzles missing.

[Lance15]

Speaking of printheads, do you guys pull printheads out and wipe them? I'm talking about those instances where the customer failed to call, let the machine sit for a month, and now has a bunch of nozzles missing.

I usually try a couple of printhead recoveries first. If that doesn't make the print a whole lot better, I'll usually pull whichever one and with an alcohol soaked towel, I'll put the nozzles on it and let it "soak clean" what it can for a minute or so, then wipe it side to side.

[Kiran Otter]

I usually try a couple of printhead recoveries first. If that doesn't make the print a whole lot better, I'll usually pull whichever one and with an alcohol soaked towel, I'll put the nozzles on it and let it "soak clean" what it can for a minute or so, then wipe it side to side.

If a head is really bad I'll see if the customer has a replacement. I'll try what Lance said, but I use Simple Green. I was told that alcohol will melt that thin plastic flexi circuity around the nozzles. The only time I find a real buildup on a printhead is the black in the 500/800. Sometimes it helps, but usually it doesn't. Maybe alcohol would help.. but I don't carry any with me.

On the belts, I've never had the issue theengel mentioned where they slip through the carriage. I've been through a few hundred belts over the years. And I'm surprised the Chinese belts last.. though my only experience was with one of them. I've been using LPS's belts lately, only because they were available and a little less expensive. They seem to hold up well. I can't really see a difference between them and the HP belts.

Kiran

[theengel]

I just use water. I soak a rag, and shake the printhead once, and then put it against the wet rag. Sometimes, for stubborn white lines, I'll tap the printhead.

I've been dealing with mailing companies and a lot of the envelope printers use HP print cartridges. From what I can tell, their nozzles are built the same as ink-fed printheads. The operators of these machines are experts at getting rid of missing nozzles. They use a really simple technique, which I don't feel like putting into words. I'll try to get a video of it and post it.

[qbert69]

I wonder if bath in an ultrasonic cleaner would "fix" the missing nozzles! I learned years ago to ONLY use OEM inks!...and not all inks are made the same! You have the Epson style inks which are pigment based...more abrasive and wear on the print head but longer archival quality...then you have the Canon dye based inks, which I prefer since they are not quite as prone to clog the print head! Although I did have a Canon that had a clog issue, I "reverse engineered"--based on an MSDS sheet, a cleaning fluid solution that was a combination of Ethylene Glycol (antifreeze) and Windex!....worked quite well and saved my print head!

[subaro]

I just use water. I soak a rag, and shake the printhead once, and then put it against the wet rag. Sometimes, for stubborn white lines, I'll tap the printhead.

I've been dealing with mailing companies and a lot of the envelope printers use HP print cartridges. From what I can tell, their nozzles are built the same as ink-fed printheads. The operators of these machines are experts at getting rid of missing nozzles. They use a really simple technique, which I don't feel like putting into words. I'll try to get a video of it and post it.

If you are going to use water, then use distilled water, it is cheap enough. regular tap water is not good for those heads as to the hardness and deposits it leaves. those heads nozzles are tiny and needs the full flow of the ink, and a thorough flush. I agree with Kiran use of simple green mixed at a 10:1 ratio and that is 10 parts distilled water to 1 part simple green. Most of those clogged heads can be recovered, but it has to be soaked for a few days in suspension method. that is the nozzles are just barely covered with the simple green liquid . There are better stuff for cleaning ink, but you have to do your homework on that with trial and error and coming up with your own solution.