Skewed ghost image - head staggered 1.5"

[genericname]

Well here's a weird one. Recently, I replaced a long overdue head on our JV4 (DX4 aqueous), as we've been hobbling along, printing only with the front bank of heads for far too long.

Long story short, with both banks printing now, I'm pretty limited by how I can print because of an abnormality. When I print in slow mode (doesn't matter what resolution), the light cyan from head 5 prints exactly 1.5" behind and to the left of the rest of the image. I'm aware from the photos that my rear Yellow isn't firing well, but that's an easy solution.

I've already swapped, replaced, and re-seated the data ribbons, cleaned the head's circuitboard, cleaned the encoder strip, and swapped out head ranking codes. I'm really just at a loss as to what could be causing this, and how to rectify it.

Help?

Edit:
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ugh... photos to follow... phone's browser is being unfriendly.

 

[signswi]

a) post a picture
b) go into maintenance mode and go through all of the fine adjustments

 

[genericname]

Here we go. Sorry about the delay there; crazy weekend.

I have gone through fine alignment settings by the way, so it rules that out unfortunately.

 

[genericname]

Update for posterity:

Noticed a gouge in the encoder strip, flipped it around, didn't solve the problem. Then decided to lift the slider board, and noticed a crazy amount of ink residue on the underside (probably from damper changes ie: pressured spray). Figuring it was causing shorts, I cleaned the hell out of it, and there's still no change.

Keeping in mind that the skewing is at a constant, exact distance from the rest of the print, I further noticed that it's also only relative to areas where Magenta is present. Measuring the distance between the ghosting and other areas of the print, as well as that of the M and Lc head proves that the two are exactly the same. The rear Lc head also seems to fire only at the point that the front heads would.

Conclusion: The rear Lc head actually thinks it's a front M head.

How to solve this, I have no idea. I've tried every mode, every speed. I can only assume that the problem lies in one of the boards. Dammit.

 

[artbot]

i'd do a data swap to see if you can get the issue to stay or move away from the head.

 

[genericname]

It does indeed do so when the data cables are redirected to another head. Doing that and swapping the cables completely eliminates both the cables themselves, and the heads as possible sources of the problem.

I've been searching for information about possible parameter changes for further testing, but can't find anything along the lines I'm looking for. Know of any software-side redirects to fool the printer into thinking one head is another?

Edit below:

I should add, for some reason this didn't seem as important before, but I know notice this puts the problem firmly between the 1394 board, and the main board.... When I run a test print from the console, everything prints perfectly, as it should be, lined up at the right height.
So the part of the printer that communicates directly to the heads is fine, as is my RIP software and station (tested on two different RIPs, with two different stations, using two different firewire cables).

HUH!

 

[genericname]

Well loooookie here. In a last ditch effort to avoid board repair/replacement, I decided to check the length of the data ribbons going from the board to the carriage system. Clean cut, right through the two last ribbons (going to both Lc and Lm heads). Bloody hell. No wonder all my previous data swaps did nothing. Looks like the front LcLm head was as equally borked as the rear, and I just couldn't notice.

Funny that it wouldn't give me an error message though. Could be that there was enough of a path to supply information, but that it was just insufficient once it arrived at the head.

Anyway, this doesn't answer questions from other, slightly related threads, but may close the ghosting as a concern. I'm skeptical though, and wouldn't doubt that I'm still getting issues once I replace the ribbons.