4027 producing light copies

[ValSupply]

Machine is producing light copies as if only using developer. Toner motor is working , have tried forced toner supply and everything along that route. All connections have been checked and look good, but cannot get prints to darken. It almost looks as if something not getting proper charge. Worked fine, changed bearings on pressure roller and hot roller, then problem arose.

[copyaction]

what have you checked?
internal prints
developer bias
laser slit glass
optics

[Jomama46]

Probably don't have the bearing seated correctly and there is no pressure between the two rollers. Disassemble and look carefully at the position of the bearings

[ValSupply]

yes i've checked all of the above and still no change. internal prints leads me to believe that's it's not the optics. the slit glass is clean

[ValSupply]

have checked them, re-checked, and checked again and still the same.

[Fearless V K]

How does the image on the drum look if you stop the machine mid-copy? These machines are notorious for drum unit mag roller or auger gears failing, also the mylars in the toner supply unit come off and can't supply enough toner. If the toner inlet to the drum is full of toner, you probably have gear failure. Maybe you messing with the fuser had nothing to do with the current problem.

[teebee1234]

I concur with Fearless, most likely the pcu. You can confirm this by turning the mag roll coupling in the back of the pcu. You'll probably feel that it's stripped, but also look at the toner input port in the front at the same time and you should see the auger turning under normal conditions.

[ValSupply]

tried another pcu that i've got here and it produced the same light image. if anyone has any ideas i would really appreciate the info. Thanks to all have helped.

[Fearless V K]

How is the image on the drum? If it is good there, you've probably got a transfer problem. Check your transfer roller and it's connection tabs to the mainframe. If the image on the drum is light, and you have tried different PCU's, then it may be a laser issue. You never said if internal prints are OK or not. Also check the connections for the drum unit in the mainframe.

[tcs04]

what have you checked?
internal prints
developer bias
laser slit glass
optics

Laser??

Isn't the 4027 analogue??

Try the charge roller! Probably black... Should be yellow.... clean with water.

[Fearless V K]

Laser??

Isn't the 4027 analogue??

Try the charge roller! Probably black... Should be yellow.... clean with water.

Not if it's a Savin, but I guess that's what I was thinking. The guy never mentioned a brand. If Ricoh, then Analog. And then maybe the transfer unit connection is unplugged, or the bias terminal under the transfer belt is unplugged. Also make sure your SP mode values for the drum and developer are at or near their defaults. I have had one where a setting changed and it gave me light copies.

[ValSupply]

the internal prints are the of the same quality. the image on the drum looks dark like it should. the connection tabs on the transfer roller are fine.
i did take the transfer roller and tried it in another 4027 and it worked fine. this leads me to believe that it is a connection problem, just not sure where to check.

[ValSupply]

this is a savin machine sorry thought mentioned before.

[gooseklr]

There were some issues with drum ground on that series. Its worth a look................
If you are not the tech that has been servicing the box you may want to check chg roller bias it may have been tweeked to compensate for drum fatigue.

[ValSupply]

that's been checked and previous tech has been consulted. have the same model in the field and just exchanged transfer rollers for one another. transfer roller from problem machine works in machine in field, and transfer roller from machine in field does not work in problem machine. once again points me to a connection problem, pin-pointing that is the question now i believe.