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JV4 neverending saga! Ink Parameters?

genericname

New Member
As an attempted work around of my issues from the previous thread, I'm wondering if I can do one of two things:

1. Scrap Lc and Lm from the print process entirely, essentially converting a CMYKLcLm JV4 into a CMYKx2 machine.

2. Reroute the information going to the LcLm heads at the board, utilizing the two spare spots reserved for the 7th and 8th heads, not present on this model.

There's no problem with simply unplugging the LcLm heads, or moving the data ribbons over two spots, into the vacant slots. The problem is when running a test, or sending a file to print, I get "Error 07 - Temp (300)" on the display, and an unending warning beep.

I'm assuming that if this can be done, it's at the parameter level. I've located a series in "InkParam1" that I think may do the trick, but I want to confirm before I go and screw anything up. The parameters I've found number 22 to 37 (Pack.1 to Pack.16). As 16 corresponds to the number of data lines available on the board, and the entries for Pack.13 through Pack.16 are blank, I figured they corresponded to the two vacant head slots.

Are these the parameters that tell the printer what heads are where? And if so, can I simply delete an entry to make the printer ignore a head? Or can I swap the information from Pack.9-Pack.12 to Pack.13-Pack.16 to make heads 5 and 6 accept data on the new streams?

Science!
 

artbot

New Member
i'm confused. the jv4 has 3 heads. at least i thought it was three. seems to me you'd just choose cmyk and not choose cmyklmlc in your rip. and the printer will just ignore the third head. after all if you've got just three heads... cmykX2 impossible.
 

genericname

New Member
i'm confused. the jv4 has 3 heads. at least i thought it was three. seems to me you'd just choose cmyk and not choose cmyklmlc in your rip. and the printer will just ignore the third head. after all if you've got just three heads... cmykX2 impossible.

Fraid not. 6 heads total (3 front, 3 back), with an extra space in the front and back for another head each, with corresponding ports for cables, allowing it to expand to a full 8 colour, 16 head behemoth, though I've yet to find someone who's done this (probably textile printer types).

When it was made, the idea was to print at the same resolution and number of passes as the competitors' machines, but at twice the speed.

Either way, short of someone knowing the inner workings of the Parameters menu, I think my only option will be to see if I can fake an ink change, and see if the printer gives me the option of converting to CMYKx2. I've tried just setting this in the RIP, but it's still using the LcLm heads in the final print.

[Small status update]:
After tinkering with moving the ribbon cables to fake a 7th and 8th head to no avail, I moved the cables back, and voila! Seemed to print fine. I thought it odd because re-seating was not the issue (I had already done it a dozen times), but shrugged and went with it. Now it looks like a degrading issue, as half way through my profiling process, the Lc ghosting is appearing again. Agh! :banghead:
 

artbot

New Member
wondered why used jv4 were so expensive used. good luck, really, sounds like you've seriously got a brain teaser on your hands.
 

genericname

New Member
why do your print tests in the other link have CMYKOG? wheres the Lm and Lc? i dont get it.

Oh, I just use that Onyx test chart in the initial ink limiting stages of profiling, because it has finer percentile steps than the default, 2% steps rather than 5%. The Onyx profiler doesn't actually print a Lm or Lc swatch, as you just set it to a percentage of their darker counterpart.

I can tell it's the Lc due to which heads are firing properly in other custom tests. The Onyx swatch just served well to Illustrate that it was indeed being offset by the same distance that's between the back Lc and front M head, but that's getting off topic, and venturing dangerously close to the previous thread's.
 

LenR

New Member
Like Artbot I am confused also.

I have configurations where I just use CMYK inks in the front and back for high speed printing. It has always been something I chose in the rip.
It would seem to me that trying to incorporate the unused spaces could become a big bucket of hurt.

Good luck on this one and please keep us informed on your progress.
 

genericname

New Member
I've tried just setting this in the RIP, but it's still using the LcLm heads in the final print.

The RIP is sending CMYK data, but the printer is still interpreting it as six channels. Kind of like printing a saturated Black, I suppose. The only thing I could think of that would change that is printing with pure hue, but that doesn't solve the problem when printing anything but pure CMYK values.
 

artbot

New Member
that just doesn't make sense (to me and i gather you are a lot smarter than i am). the rip and the firmware talk to each other. your printer shouldn't be over riding what your rip says to do. i think if you fool with this you find out a way to shut those heads down. hell, you can just plug in damaged/clogged heads in those spots and it won't matter.
 

genericname

New Member
that just doesn't make sense (to me and i gather you are a lot smarter than i am). the rip and the firmware talk to each other. your printer shouldn't be over riding what your rip says to do. i think if you fool with this you find out a way to shut those heads down. hell, you can just plug in damaged/clogged heads in those spots and it won't matter.

Plugging in damaged heads is definitely a quick easy way to remove LcLm from the equation, though that was always just my backup in case I couldn't get them working properly.

I agree that there shouldn't be interference from the printer regarding information sent to it via the RIP (barring a change in priority settings on the printer side, but still). It's plain enough to see that the Lc is still firing though, even when set to use only CMYK in the RIP, because it frequently fires clear accross a captop on its way to the actual print area. This was discovered recently, which would mean that it's not just emulating the front M head, in printing at 1.5" behind and to the side, but that there is a genuine communication error of some kind going on.

Edit:
With the above being said, I think it's safe to say that the issue stated at the beginning of this thread has been tackled. Switching data lines simply isn't possible without further knowledge of the inner workings of the parameters menu, and removing LcLm from the equation altogether is easily done by replacing their heads with a couple that won't fire anymore. The rest of this thread is getting dangerously close to tackling the original issue, already discussed in a previous thread, and we don't need to clog the forums with two conversations about the same thing.
 
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