Phaser 850 Maintenance Drawer - Oil Roller Lift Pins 1

[oldirontech]

A Tektronix 850 arrived at our office for repair and I am not yet familiar with its particular design flaws. Pages stick to the imaging drum, presumably because of insufficient oil transfer. The customer has replaced the oil roller in the maintenance tray. I have confirmed the proper operation of the clutch - the cams are positioning as expected, but the oil roller NEVER moves. I noticed that the lower halves of the lift pins are flat - should they, in fact, be rounded? This would seem a likely explanation to my problem. Should the cam followers also be replaced? It would seem that the pins wear because the lift motion is not straight up and down, but includes a horizontal (sliding) component. If this motion erodes the lower halves of the pins, it stands to reason that it also files away on the cam followers - actually, the lower halves of the cam followers probably erode due to riding on the cams.

Please pardon the length of this post (it's my first - I'll attempt to be a bit more terse in the future). I should just like to know if I am on to something here.(?)

Thanks

 

[J0S]

The wear of the lift pins is a known problem for the Phaser 8x0(0) printers. The only thing you should do is fix the pins. With some plastic strips (usualy used to tighten loose cables) put over the pins, this problem can be solved.

 

[oldirontech]

Thanks (JOS) for the advice. I ended up epoxying a small, hard plastic (had to trim it down to size) cylinder on each lift pin and one problem is solved. The paper no longer sticks to the drum, but the image quality is horrible. There are about a dozen light streaks down the page.

Running "eliminate light streaks" several times had no positive effect. In fact, the problem only seemed to get worse. I pulled the printhead and examined the c/w/p assembly. The gasket was caked with wax, and there was a fairly large clump on the lower, left corner. So, I removed the c/w/p and cleaned the gasket. BUT, the printhead also has a substantial amount of wax in the area where the gasket is supposed to seal. Is there a safe method of removing this wax, or should this be left alone? Does this wax build-up interfere with the sealing of the c/w/p on the printhead surface? Again, I am ONLY worried about the wax which is located around the perimeter of the printhead where the c/w/p gasket makes contact.

Thanks again.

 

[J0S]

Normally it should be safe to clean the frontplate of the printhead. It is probably for the best that the area where the head and the c/w/p meet, is clean.

 

[oldirontech]

THAT'S A RELIEF! I actually used a soft, damp cloth (designed for cleaning imaging drums) to remove the buildup from around the periphery of the printhead. Afterward, the print quality was even worse than before. I'm pretty sure the c/w/p is bad. The gasket cleaned up nicely and I didn't see any areas where it was separating from the cap, but there was a good deal of color variance in the material. A vacuum check indicated a very poor, short lived seal - the vacuum didn't ramp up to the level indicated in the manual, and it dropped off almost immediately to nothing. After testing/cleaning, there was a lump of wax in the same area of the gasket as before. I suspect it's time to get a new c/w/p assembly, eh? Could it simply be misaligned?

Thanks (JOS) for your advice - I sincerely appreciate it.

 

[Smaug1Tech]

Howdy,
Take a look at the rubber vacuum line to see if it is split, or not slid on to the c\w\p pipe all the way.
It is perhaps the c\w\p itself has the problem. Replace it.
Check the belts on both sides to see if the belt-connectors have loosened. You can hold them and squeeze tighter a little.If they have been removed, make sure of the correct placement of the c\w\p before tightening. Luck,

 

[aborack]

It seems that the lift pins become worn beyond use at about 60,000 copies. I had to have a tech in from Xerox $395.00 to clear paper stuck to the drum. He said that the lift pins are worn by defective guide rails in the unit. The guide rails gind a little material off of the pins each time you move the tray in or out. If your 850 or similar machine is under warantee, have the guides replaced. They are cheap, just a dollar or two, but the labor is a killer. If not, you might want to try to replace them yourself. I heard of one person who lubricated the guides monthly with liquid silicon, but I am not sure if that will create other problems.