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Installing your own heads?

MikePro

New Member
Anyone out there have any tips for a first-timer looking into possibly installing his own print heads? A technical manual is one thing I can handle working from, but mainly looking for personal experience stories/reminders of things I should look out for.
 

artbot

New Member
i'm a newbie that recently had to change a jv3 head (160sp). the back hex screw is pretty hard to access. next time i do it. i'm going to buy a longer allen wrench and put a slight bend at the end. also, it's really tight. take off all the ribbons and all the dampers. i recently put super long mutoh ribbons on my machine and it really opened up a lot of finger room. also, new dampers can sometimes fit much much tighter than older ones or different manufactures. put the damper on the head on and off a couple of times before it's installed to make sure it's going to go on. don't twist it on. i broke off an adapter nozzle, ended up with white ink leaking everywhere and fried a head that way. and lastly, go to the hardware store and buy an led snake light. it has a tiny light at the end of about a 1/4" cable. you can clamp it to the cover and point the light very accurately at the place that you are working. i also have installed LED lights inside of my printer housing and have a special spot light in the ceiling pointed directly at the park point of the head carriage. i like a lot of light to see what's going on. after you install lights inside your machine you can't stand printing with them off. too shadowy.
 

MikePro

New Member
Mimaki JV3-160SP.

SignSupply also recommended changing the dampers while I'm at it, which seems reasonable considering I'm exposing those parts to air while i'm working on swapping the heads out. AdvantageSupply has been really great at helping me diagnose the problem thusfar, I'm tempted to have them install it, but my boss isn't too thrilled with extra expenses lately... new accountant, and tax season, making it very hard for me to request expenses.

So mainly just looking for some, "its easier than you think" posts to push me over the edge. Artbot's got me thinkin' already!
 

artbot

New Member
for the dampers, order a bagillion dampers for $5 a piece from a chinese distributor and go through them like paper towels. also order some fresh ribbons for $3 each. the chinese ribbons are very heavy duty compared to the stock mimaki ribbons. also, i was a bit concerned about static charge. when you work on your printer turn the back switch off but keep it plugged in. to be even more anal about it. take and old computer cord and break off the positive and negative and just plug in the ground. but keep the printer plugged in. that way it's earth grounded. as far as yourself. if you want to go the extra mile. take off your shoes. rubber soles keep you static charge trapped in your body (for that matter, don't wear latex or rubber gloves either). don't scuffle around a lot. have all your tools at the machine. and every time you get near the electronic parts, with your left hand, briefly touch the printer platen. this insures that whatever minute charge you might be carrying is dispersed into the ground.

the first time you do it, it will be foreign. i changed out many dx2 heads. but the dx4 was new and more clumsy. but now i can pop out a head and get it back in within about 15 minutes.
 

MikePro

New Member
thanks for the tips! Unfortunately, but hopefully, I'll be bugging you guys soon about alignment! Thewood was kind enough to remind me of the mimaki files on yahoo usergroups, but the alignments page has me a bit confused.
 

sigmo

New Member
when you work on your printer turn the back switch off but keep it plugged in.

I'm afraid I need to strongly disagree with this statement. I am a printer tech with many years of experience and this is the leading cause of frying a mainboard. ALWAYS unplug the printer before working on any electrical components. You also risk electrocution.

Swapping heads is not too difficult. Diagnosing problems like air leaks, capping station seals and pump operation are not always so easy and if there are these issues they will manifest during a head swap for sure. They may even be the cause of what appears to be head failure when in reality the head is fine.

Air leaks can be identified by printing a nozzle test print, doing a head clean, and repeating this procedure a couple times. Now look for missing lines in the test prints. If there are several that jump around between test prints it's air leaking into the head between the head and the cartridge. Dampers, "O" rings, ink lines and the parts associated with where the cartridge connects need to be examined. If there are several missing lines "gaps" in the test prints after installing the new head which DO NOT jump around the issue lies beneath the head - the capping station and pump should be examined. Also, always clean the rubber wiper blade which cleans the bottom of the head. A dirty wiper will push dried ink into the nozzles of the head and this can be identified as a possible source for missing nozzles too.

Lastly, get your hands on a service manual, and read it.

Regards,
David
 

artbot

New Member
as far as diagnosing patterns. a pattern with a missing halo in the middle of the pattern is a sign of a faulty head adapter. missing high or low points on the test draw is a sign of misaligned caps. that area isn't getting proper vacuum from the refresh. thus starved for ink.

as far as unplugging the machine while working on it. that is NOT recommended. no where have i seen or heard this. at least tear the positive and negative off a cord and just plug the ground into the printer. keep that thing earth grounded. what is the point of the manufacturer going through the trouble of grounding the machine if you are going to unplug it while working on it.
 

sigmo

New Member
Diagnosing test patterns is great information but please, never work on any electrical equipment while it is still plugged in. If you are concerned about static buy a grounding strap which goes around your wrist while the other end is grounded. They are only a couple dollars.

I'm serious, this is BAD.

I've included a screenshot of the Mimaki JV33 maintenance manual which says to turn the power off and unplug the machine before working on it. I'm not looking for a fight, I just don't want some poor person ruining their equipment, or worse, getting electrocuted trying to save a buck working on his/her own machine.

unplug.jpg
 

MikePro

New Member
i like the idea of grounding the unplugged machine. I mean, it couldn't hurt right?
I was definately NOT planning on working on it while being plugged in.
As far as diagnosing goes, I'm pretty much set. I've exhausted any other option other than a print head. Also after picking brains at ISA I've gotten plenty of confirmations that it can't be anything else.

I even plan on flushing out my inks prior to working on the head, to avoid any potential mess that may occur... Is it safe to say that its less risky to swap heads that are primed with cleaning solution rather than ink?
 

macmedia

New Member
no need to flush out inks when you change the head/dampers. The ink will automatically flow back into the cartridge area when you remove the dampers.

Make sure you have a large syringe (60cc) so that after replacing with a new damper, you put the syringe to the bottom of the damper and draw ink into it slowly. Fill the damper only halfway.

Write down the head rank off of the new print head. CAREFULLY flush out your new print head with some cleaning/flush fluid. Better to take a new damper with tubing and connected to the syringe, attach it to the head nipple and gently insert cleaning fluid through the nozzles. Not doing so and you will experience clogged nozzles that you will have to clear later on. Replace the head and put the dampers back onto it.

Enter in the new rank into the front panel and do your calibrations.

This is an extremely compact instructions of the install but by using the syringe, you won't need to do an ink fill from the panel as the head will be already primed and ready to go.
 

artbot

New Member
the correct procedure is to:

turn off the machine on the front.

turn off the machine on the back.

shut off the switch on the surge protector.

tap the front button once, twice, three times if needed. the green light will light until the final amount of latent energy in the printer is dispersed by the button lighting.

and then work on your machine in the most grounded fashion and behavior possible.

the only electricity at this point that your printer will have in it will be the ESD that you bring to it.

maybe a tech does is trained differently. i'm just a guy that's been repairing his own roland, epson, encads, and mimaki for the last 10 years.
 
artbot, respectfully that is NOT the correct procedure. you are passing along erroneous information that could have very expensive consequences and possibly deadly consequences.

i can not stress this enough. anyone who follows your advice is putting their equipment and their safety at risk. i wish there was a way to have your comments on this topic deleted because they are truly dangerous, what else can i say?

please anyone who reads this series of responses. excercise good judgement and common sense. UNPLUG YOUR MACHINE!
 

Rooster

New Member
Every service technician thats ever touched one of my machines has done it while the machine has been unplugged.

Every time I service my machines they are unplugged.

I've had to replace a couple of motherboards over the years. For the sole reason that I forgot to unplug the machine from the wall before servicing it.

Unplug the machine. End of story.
 

artbot

New Member
well, i don't know if the motherboards an mimaki's are AT or ATX. if ATX than not discharging the capacitors by several pushes of the front button was the cause. unplugging the back will not discharge any capacitors. also a power supply has capacitors that can stop your heart without being plugged into anything. so all this unplugging business to me is very generalized. i think it's strange that in the
"precautions of maintenance" screen capture it does not require discharging the capacitors from the front power button.

how about this. FOR THE RECORD. only artbot will leave his printer grounded. i advise everyone else in the signs101 community to adhere to the service manual. so if some potential voltage issue occurs we will know that the mamaki gods are to blame.
 

MikePro

New Member
Bumped to thank everyone again for the tips! Its cool to have people around that make it seem so simple... takes the edge off my first experience with swapping heads.

All-in-all, i've pretty much got the process down. My first head took me about 2hours since I was being overly cautious about EVERYTHING... now, heads are in/out now in <30min. Alignment is a PITA but manageable. I'm loving it!

Now I just gotta find where I saw printheads for under $600, since I wanna order another! While i'm at all this, then I may as well have all 4 heads running fresh, with an old head around for diagnosing/emergencies.
 

MikePro

New Member
o, and if anyone was curious... no i did not electrocute myself :)
powered down, both switches off, pulled the cord, and flicked both switches on/off a few times (the front switch did light up, and powered down, like a computer discharging)

I even took off my shoes/socks to avoid myself being the static charge-carrier.
Touched nonessential metal parts of the printer, religiously, as extra precaution.

I'm still missing a few screws, however... don't really need the carriage-head cover, right? Looks cooler without it, imo.
 
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