HP CM1312nfi epilogue and bewilderment

hat ?

was pretty much automated and the process was simple. Print the test page and then scan it., After that it put in all the parameters. Pretty much str aightforward and not hard to figure out how the process works.

I hear a motor start up and thew display reads "calibrating" or something to that effect. So far so good.

ame one I had printed before that showed the registration errors.

is thing have Xray vision or some shit ? How did it know the registration w as off and how much and what direction ?

is bothers me. How in the hell can it set the registration without some fee dback concerning the error ? Perhaps detectors right in the toner cartridge s or something ?

ming. If so this post will not appear on SER and we can go back to thinking we know everything.

I have an inkjet that does its alignment like this. Put new carts in it, an d a few minutes later it says "Aligning" and aligns itself without printing a test page, let alone needing to scan it.

Yeah, and just how the f*ck does it do that ?

Purely guessing here:

Might be some impossible to see registration marks on the inside of the scanner cover which are seen at UV frequencies only.

Could be visible markings which are normally concealed because the scanner cover is down / closed.

Inside scanner cover may have a deliberate "texture" designed to be used as a calibration "graticule"

Possibly on some models, but I didn't scan anything. This remains a mystery . Is it possible though that it reads right off the rollers ? Sensors on th e transfer plate ? The service manual of course gives underwhelming detail on the thing......

I dunno. I really didn't read all 300+ pages of the service manual, I looke d real hard for the registration process and didn't find it. And then the t hing starts humming and it fixes itself. That IS how it happened. Afterward it printed fine, registration was right on the money. I never scanned anyt hing or even pushed a button.

For now, the most likely answer according to Occam's razor is VOODOO !

Less bewilderment.

The laser assembly I took out ? How long did you think it was going to sit there before I took it apart ? OK, now this is a bit unusual, but a friend of mine took it apart before I did. he was there and said "got a phillips ? ". I should have known better but you know, I don't care.

Regardless, I finally took it apart myself. I looked at it intensely, there is a motor with a four sided mirror. There are all these other mirrors and lenses. Once you see it you get the idea how it works. In fact if anyone i s interestec maybe I'll take it apart again and get some pictures, but for now....

I am pretty sure I fixed it. I looked at that four sided rotary mirror and it did not look shiny. Quite dull in fact. Remember I said it was not in th e best of environments ? We are talking four heavy smokers in a small house . That small house also means that between laundry and cooking it was also quite humid.

The gunk on the mirror was not hard to get off with a Qtip.

There was never an issue with tomer at all, or high voltage or anything els e, it was simply that the LASER beam could not get out of the box. Now if t he replacemetn fails I have one.

So what is the air flow path that allows gunk in there? the ones I've looked into are sealed units with no ventilation requirement

Good question. It looks open to me but there could be pieces of glass there. There are no gaskets or anything like that.

That little motor does not need airflow like a Phase Linear 700, and the LASERs are not even in there, they are on a PC board off to the side. The unit could easily be sealed and still work.

I also wonder how this stuff got attrac ted to the one mirror in the moiddle.

It was a matte finish, metal color not dark. Not brownish at all. It wiped off with a Qtip.

What could it have been ?

Is the dirty Qtip attracted to a magnet? Maybe a magnet inside and a hall-effect somewhere for synching and a worn bearing somewhere

I can't really answer that, the Qtip is history. Even if I had it though, t he surfaces I cleaned were so small that I may not have been able to tell i f the particles were magnetic. We are talking about 2.5mm X about 15 mm or so. That is not alot of gunk with which to work.

What this means though is that I have pretty much every major component spa re for this thing. The donor unit had a bad transfer plate, it was obviousl y FUBAR. Tell you this much, I think a cat pissed in it. A little corrosion here and there y'know ? Far as I can figure now, other than the transfer p late being bad I got the HV board, which I did change and didn't bother to cvhange back. The fusert is an item to have as well. I already started cutt ing on the original black toner to see