PROBLEM/SYMPTOM:

Excessive toner consumption and waste toner bottle overflows. Most noticeable in applications of short batch and start-stop print jobs.

CAUSE:

Earlier versions of the Engine Controller (EC) firmware would cause the Laser to scan "full-on" upon initialization of the OPC drum cleaning cycle. Also, earlier EC versions engaged the developer voltage at the same time as the OPC drum charging corona. Both of these effects could cause the OPC drum to develop a considerably large area of solid toner fill. This block of toner would be cleaned off during the cleaning cycle and be deposited into the waste toner bottle. Variations in toner may exaggerate this effect.

SOLUTION/PROCEDURE:

Check the EC firmware level by means of the "Extended Configuration Menu" or by printing the summary page. There are two different groups of EC firmware, versions that begin with a "001" and those with a "010" designation. The EC firmware must be greater than V1.25 (001-025), or greater than V10.27 (010-027), in order to correct this problem.

Units with EC firmware that have the "010" prefix, only require the EC firmware chip to be replaced to complete this modification.

Units with EC firmware that have the "001" prefix, will require the firmware chip and a 10k ohm resistor added to the controller PWB. The resistor will not interfere with earlier versions of firmware. Refer to section 6-40 of the maintenance manual for instructions on how to remove and replace the controller PWB. The EC firmware chip is the only socketed EPROM on the controller board.

Once the controller is removed, and the EC firmware EPROM has been replaced, use the following rework instructions to add the 10k ohm resistor (where required).

1. With the component side up, locate J7.
2. Rotate the board so the component side is down. Locate C132 and J7.
3. Install a 10k ohm resistor (PN113-10103-00) between C132 +5Vdc side and J7 pin 6, as shown in figure 1.
4. Clean the solder areas of flux and inspect for cold solder joints and solder splashes.
5. Re-install the PWB and test the printer.