Photoconductor unit is not set properly - Gestetner DSm725 Color Copier

Please open the front door carefully and open the right door also and then remove the photoconductor unit unit and reset properly.
If the problems persist , call an expert to check the sensor for you.
Best of luck.

What did you repair? as the pcu is an assy and cannot be rebuilt

Sorry but photoconductors are handled only by technician, tis is to avoid damage and correct handling it is set to its standard settings to have a good copy quality. before inserting or setting the photoconductors the machine is to be cleaned thoroughly. so let it be handled by a photocopy technician even you pay or not for its services, it is worth it.

Here is an excerpt I found from the W840 user manual. Looks like you need to change the photoconductor kit. Here is the link for the user manual: images.lexmark.com/publications/pdfs/w840/eng/ug.pdf
To ensure print quality and to avoid damage to the printer, the printer stops operating after the photoconductor kit has reached approximately 60,000 pages (Letter/A4). The message 84 Replace PC Unit is displayed when the printer reaches this point. If the Toner Alarm setting is set to Single or Continuous (default is Off), the printer automatically notifies you before the photoconductor reaches this point and displays the message 84 PC Unit Life Warning. To avoid having the printer stop operating, replace the photoconductor kit when you first receive the 84 PC Unit Life Warning message. Once the photoconductor kit has been replaced, normal printer operation resumes

84 replace photoconductor on the display indicates that the photoconductor has reached its expected life rating. You may continue to print but will be at risk for developing print quality issues. It is recommended that photoconductor unit be replaced. After replacing a photoconductor unit, you will also need to manually reset the PC counter,

• Instructions on how to replace photoconductor unit available at http://bit.ly/aykTXL
• Instructions on how to reset photoconductor counter available at http://bit.ly/9WAvUK

Thanks

Here's an article on How to Change the Photoconductor Unit/Kit on a Lexmark E250d(n), E350d, E352dn, or E450dn Printer. Just click on this link: http://bit.ly/aykTXL. This should give you an idea on how to install the photoconductor unit in the Lexmark E352dn printer.

NOTE: If you are replacing your old photoconductor unit with a new one, after installing it you will need to reset the photoconductor counter as well.

Order the specified photoconductor unit. When print quality is reduced, install the new
specified photoconductor unit using the instruction sheet that comes with the replacement
specified photoconductor unit.
Good luck, Gerrit Jan

You will need to get the photoconductor unit replaced.

You can get detailed information about the same from:
ftp://download.epson-europe.com/pub/download/205/epson20540eu.pdf

1. Check of Photoconductor Unit attachment. Re-attach Photoconductor Unit.
2. Is the Drum of Photoconductor Unit rotating?
3. Remove Photoconductor Unit. Turn gear of Photoconductor Unit until silver seal attached to Belt can be seen.Is silver seal dirty?
4. Remove Photoconductor Unit. Is SENSOR TR-0 attached securely?
5. Remove Photoconductor Unit. Are there any dirt or foreign bodies on the SENSOR TR-0 surface?
6. Does the error recur when the power is turned ON?
7. Remove Photoconductor Unit. The voltage of P416-2 ↔ P416-3 on PWBA MCU is 5 VDC when silver paper or other reflective object comes close to the sensing area of SENSOR TR-0, and is 0 VDC when the object is released?
8. The voltage of P416-1 ↔ P416-3 on PWBA MCU is 5 VDC?
9. Disconnect the P/J416 from PWBA MCU. Do all of the wiring below have normal continuity?
10. Replace MOTOR ASSY P/R.
11. 
    

Turn printer off and remove photoconductor unit, close covers and turn printer back on without photoconductor, error will appear that you need to install photoconductor, install photoconductor and wait til it calibrates, if same error appears photoconductor is a consumable part you will have to replace it then.

Pls dnt 4get to rate solution. TY