Colour misaligned on MP C400

[sandmanmac]

It looks like the colors are too far off for the color registration to be able to correct it. Before going the cost of a new laser unit you might want to try doing a manual adjustment. Since all three colors appear to align to each other and only the black is off, try changing SP 2101-001 and see if the black moves in reference ti the colors and in what direction. If it does, but not enough or in the wrong direction, try a different value.

Thanks Tim.
I had originally adjusted the 3 colours with SP101 (006-008), because it seemed to be those that were shifted, but when considering it a little more, a shift of black alone could cause the same result, and I was actually able to adjust black (SP101-005) and get them aligned properly again -for the colour test pattern at least

Here's the thing now: I left the client the other day after manually aligning and getting the colour test pattern perfect. They called me a couple hours later to tell me that the colour had shifted again.
I went back today and the colour pattern was still perfect, so I asked them to print something, and sure enough it's really blurry.
I ran the Line position adjustment, and printed the test pattern and it's off by several mm's like the samples I've attached. I ask them to print another page, and it's perfect!
So, I'm basically back to where I started in this thread - only internal test patterns seem to be affected at this point.
Also, As I mentioned earlier, the Non-default printout is missing the majority of the info - it's just over a single page of data.
The firmware I have is over a year old, but I re-wrote it all just to see if that would help, PLUS I have another machine in my shop running all the same stuff without an issue.
Now, It feels to me more like a controller issue or something, rather than laser

[slimslob]

SP 2101-001 is specific to each black laser unit. When you replace the laser unit, the value is on the settings sheet for the new unit. If something has caused the black unit to be thrown off then you may need to do a trial and error adjustment. I would start with a value between where it was originally and where you changed it to. After changing it, do a forced line position before printing the test pattern.

[sandmanmac]

SP 2101-001 is specific to each black laser unit. When you replace the laser unit, the value is on the settings sheet for the new unit. If something has caused the black unit to be thrown off then you may need to do a trial and error adjustment. I would start with a value between where it was originally and where you changed it to. After changing it, do a forced line position before printing the test pattern.

Thanks Tim,
SP2101-001 thru 004 moves the image horizontally, and 005 thru 008 move them vertically, so I've only adjusted the latter 4 numbers because it was only a vertical shift, and was able to get it perfect with little trouble. They were all "0"to begin with, and are set back there now. I can't tell you right now what 001 thru 004 are, but again, that only affects the horizontal position which is not an issue
On another note. I've just been fooling around with those SP's on a machine I have here with me. It works perfectly, and all 8 of the SP's are set to "0". Just for fun, I set them all to random numbers between 10 and 50 and got a really bad test pattern as you can imagine. I ran the Line adjustment and it came back perfectly, so I'm still not clear on what the point of entering all the pertinent info is
Again, I'm also stumped by the fact that adjusting the settings so that the test pattern looks good, makes prints and copies look like crap

[BLADE]

the black density doesn't look right (which is the ref point)