Head gone crazy?

[Conor Knoxx]

I have a ValueJet 1204 - 4 years old now, and the only "maintenance" I've ever done is clean it (I'll admit I'm somewhat intimidated by more advanced procedures!)

Its quite a low-volume shop - I'd say a set of cartridges every 2 months...

Recently, the magenta has become erratic. One of the heads (the right hand set when you do a print head test) just completely stops firing, in the middle of print jobs. If I shut it off, then on and do a head cleaning, it "comes back to life" every time - while other times, it suddenly will put a light magenta "sheen" over the whole area its printing (like its firing continuously) - again, if I shut it down, and restart, it seems ok for a while..

I'm ruining about 25% of my print jobs now though, so I can't just "live with it" anymore. The company I bought it from no longer deals with mutoh, and I haven't even found a good place to get parts (I'm in Eastern Ontario Canada)

The second problem (not as critical...) is the cyan head - again, the right-hand one - on a print head test, leaves exactly 50% blank - eg: instead of solid/stepped lines, I get dash - space - dash - space thoughout its pattern.

Any insight or help sure is welcome!
Thanks in advance!
Conor

 

[Lincan]

sound like some air in your ink tube system

 

[Gabriel]

...or you might have some damper problems. Try to perform some powerful cleaning and then make a nozzles check. If the problem is still there, you might need some new dampers. If you replace the dampers and the problem is still there, maybe it would be better if you call a technician.

 

[henryp]

Magenta nozzles dropping out after a while: ink starvation, possibly blocked filter on damper or air leak, replace damper.

Magenta nozzles intermittently firing all the time: most likely an electronic issue, check head cables, make sure they are correctly inserted.

Missing print on Cyan: blocked printhead nozzles, soak the head or do a head wash

 

[CheapVehicleWrap]

yep, agreed. You're well overdue for dampers. replace them all.

 

[Conor Knoxx]

thanks for tips and a direction to start in!
Sounds like first thing is some serious cleaning (flushing?) and ordering some dampers then.

I'll take the end apart, and see how things are flowing when I do a head flush.
I feel like I owe the poor old girl some TLC anyway!

I've seen so many posts here about having technicians in, and at best, the problems aren't solved, and at worst, they're worse! So I'm a bit skeptical of calling someone in, before I do a bit of troubleshooting myself. I really enjoy "learning" this stuff, and am pretty mechanically inclined... I just worry about putting myself out of business for days on end because of some stupid mistake!

I'll post results / updates in the next few days.
Thanks again!
Conor

 

[Conor Knoxx]

so.. I've found one of my suppliers can get me Mutoh parts... so far, so good!
I figure I'm on the right road here, when he asks "standard size, or over-sized dampers?" gah!!
any easy way to tell?
All I know for sure, its the original factory ones in place - however I assume they are not interchangable - so if it needs "oversize" standard is not going to work...

any insight is appreciated...
otherwise I guess I'll order "standard" and hope for the best!

 

[Gabriel]

You made the right choice! Those are small dampers for 1204. The big ones are for 1604 model. Good luck!

 

[Conor Knoxx]

ordered dampers...
meantime, things kept getting worse.
I could do a cleaning, get a magenta head-test pattern, print 10 inches or so, and the inside magenta head would quit.

It wasn't a gradual bleed off either. One line perfect, next line nothing.

Do a head check - the inner magenta was 100% missing.

My concern was, that I was waiting for dampers, and not sure this was actually the problem - so I decided to swap the 2 dampers, and see if that reversed the problem.

NEW PROBLEM: took out the wrong screws / assembly, and started removing the actual print heads. Realized the error before I got too far, and re-seated it.

Removed dampers cover. I could see right from there, all the dampers were "full" except the not-firing magenta - it was down a about 1/4 inch in the damper.

I pulled the dampers, and to make sure ink was flowing in, I used a syringe on the bottom of the damper to draw ink through (had to block one while doing this, since it would just draw from the other damper) which seemed to pull through fine / easily.

Swapped the dampers, and re-assembled. Powered on. Got a "head heat" error (tried several re-starts). Removed screws on the head, jiggled it around a bit (seemed like it was in place..) and re-assembled.

Error cleared.
Now I'm not getting any magenta whatsoever.
Tried 3 head cleanings (not seeing much ink drop down from the waste tubes) and not a single pixel of magenta will print.

Any thoughts?

I'm thinking its time to give in, and call a tech.... might be expensive, but so's "being out of business" !

 

[Conor Knoxx]

Update

UPDATE
let it sit awhile... did another cleaning, and another head check.

the "missing magenta" has swapped sides!
which really tells me that it IS in fact the damper, since the reversed dampers have reversed which head is not firing.

 

[Conor Knoxx]

nope... I was wrong again! (I'm so good at being wrong, lol )

the inner magenta used to work intermittently / outter one always perfect.

Now, after swapping dampers (and screwing things up) the inner is still intermittent (just "thought" it was working ok) and the outter no longer works at all (was fine before I got my fingers in there.. )

 

[Conor Knoxx]

dug back into the guts of the beast last night...
- I definitely messed up the head position when I moved it. Cleanings were not drawing out any ink.
- took the head completely out, then carefully replaced it into the correct position.
- cleaning is working / drawing ink again
- nozzle check results in outer magenta printing fine / inner will sometimes fire, but still quits after a few lines.
- set "effect" to "B - Superfine" so I only use one set of heads (what a great tip, from another thread here!)
- the non-firing magenta does have a couple of air bubbles in the line, however since swapping the damper and its attached line didn't help, I think this is not relevant right now (also its "turned off" so it would only draw a bit of ink when doing a cleaning, so I suspect a couple more cleanings and some printing would clear the bubbles)
- LONG STANDING PROBLEM: cyan - one head is perfect, second head is "dash-space-dash" completely even throughout its nozzle pattern (so it skips every other dash/step) this has been this way for over a year, and never changes pattern in slightest, regardless of cleanings.

Do I need a new print head?

I'm finding it hard to even find a tech that will come out here (near Kingston, ON) so I'm thinking I'm really "on my own" on this one. I feel much more confident I can fix this myself now though, since I've had so much of it apart and back together now...

Some thoughts / insight is really appreciated at this point though! A print head is pretty expensive, if I don't need one.

 

[Compilla]

Do I need a new print head?

Yes, it's been 4 years of service. Replace the head and be done.

 

[Conor Knoxx]

I've got no problem with replacing the head.... unless it doesn't fix the problem. So I'm trying to be "as sure" as possible first.

Here's one of the symptoms.
Was test printing a red rectangle, when at the end of it, the magenta starts this "continuous firing" nonsense.

shut down, tried some straight green text (twice) and it was more of the same... (so the top 2 lines were just green text on white background)

Head failure?

I did test swapping of the 2 magenta dampers once more, to verify that wasn't the problem, and it made no difference whatsoever.

 

[randya]

Continuous firing is typically either be failing head or bad cable or both.
A bad cable can take out the head.

 

[Conor Knoxx]

Thanks Randya,
I'm getting a quote of $2375 for a new head (Canada)
Sound about right?

Sounds like I'd be wise get a new ribbon cable while I'm at it too.

 

[randya]

I dont do much pricing, so not sure, with the exchange rate and all.

 

[vroongraphics]

get a quote from Canadian Sign Supplies. Their tech is a great Mutoh guy....

www.cssupplies.com

 

[Conor Knoxx]

well, time to close off this tale...
shortly after posting the price of the head, I got a PM from Kent, at Mac Media.

He had a better price on the original Mutoh part, but more importantly explained to me that I could use an Epson head - just had to change the manifold on the back of it. This was $1300 - an awful nice savings from the nearly $2400 I was looking at!

I decided with our postal strike, and gestapo-minded customs folks, it was best if I drove to Mac Media to get it - 1000km round trip... what the hell, couldn't work without my Mutoh anyway!

Kent was extremely helpful!
He happily spent some time showing me "hands on" how to change the head, dampers, etc - and get everything primed up and running again. I came home with 1000 times more confidence, and felt much better about doing future maintenance!

The only "glitch" I ran into during the changeover was right up there with "did you check that its plugged into power?"

Try as I may, I couldn't draw any ink into the heads (dampers were all charged up) with the cleaning cycles. On the edge of total nervous breakdown...
I noticed I still had the head-height lever in the "up" position ! :Oops:


dropped'er down, next head cleaning got about 75% of nozzles firing, and one more got them all!

Thanks for everyone's help! We're up and running better than we've been in a long time! Hopefully this thread will help someone else sometime.

And if anyone needs knowledgeable help, give the boys at Mac Media a try!