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907tec
07-02-2010, 08:48 PM
Has anybody else experienced this code? Not much of a description in manual, just says K write unit failure and to replace. One mention in the Solutions Database, saying the same thing. From what I've heard, it's not a good idea to swap a color unit with the K unit for testing, though the only difference I can see is the TEMSB sensor.

Anyone dealt with this code before? Should I just bite the bullet and order a new K write unit? Any additional parts that I should replace at the same time? Customer only has ~850k on the machine, less than a year old.

Thanks again for the help.

DUKEY
07-02-2010, 10:31 PM
Did you try upgrading the firmware to the latest level? it's worth a shot if they have 850k they have had it for a while! firmware may help the contrl bds

Stirton.M
07-03-2010, 12:34 AM
I agree with Dukey.

Also, replace the IPB (image processing board) if you have a spare unit. Check the 12V signal related to the laser unit.

Usually, I defer to the TSBs when other avenues have been checked out. It is quite likely the laser unit.

The service manual relates to the number of connectors as being different between the colour and black units. Not sure if this means separate wires or physical connectors.

HORSE
07-03-2010, 10:41 AM
I have had an issue with intermittent C-4721, a pin on the connector on the IPB was pushed back when the plug was pushed in (but when it was unplugged the pin would pop out and look normal). The tip of the pin was just about sitting in the hole of the plug but now and again the vibration would cause a disconnection and throw a fault.

Replaced the IPB to solve it in the end (wasnt worth messing around with the old board)

There is an extra Physical connector on the K unit for the Temperature sensor.

texchar555
07-25-2010, 06:44 AM
check for pinched wires on wire harnes on the back of the process unit. replacing image units will knock off the black plastic cover off.

jma676
08-19-2010, 12:33 AM
Has anybody else experienced this code? Not much of a description in manual, just says K write unit failure and to replace. One mention in the Solutions Database, saying the same thing. From what I've heard, it's not a good idea to swap a color unit with the K unit for testing, though the only difference I can see is the TEMSB sensor.

Anyone dealt with this code before? Should I just bite the bullet and order a new K write unit? Any additional parts that I should replace at the same time? Customer only has ~850k on the machine, less than a year old.

Thanks again for the help.



Solution ID TAUS0701674EN* Solution Usage 14
Description
C-4718, C-4719, C-4720 or C-4721.Depending on the code indicated, the three other malfunction codeshave not been registered.
Solution
CAUSE: Write unit failure.
SOLUTION:Replace the write unit.
bizhub PRO C5500/C6500 write unit:
p/n A03U R712 00- color
p/n A03U R71100- black

jma676
08-19-2010, 02:07 AM
I agree with Dukey.

Also, replace the IPB (image processing board) if you have a spare unit. Check the 12V signal related to the laser unit.

Usually, I defer to the TSBs when other avenues have been checked out. It is quite likely the laser unit.

The service manual relates to the number of connectors as being different between the colour and black units. Not sure if this means separate wires or physical connectors.



According to the Service Manual.

MPC ( Maximun Power Control )
APC (Automatic Power Control)

jma676
08-19-2010, 02:15 AM
I agree with Dukey.

Also, replace the IPB (image processing board) if you have a spare unit. Check the 12V signal related to the laser unit.

Usually, I defer to the TSBs when other avenues have been checked out. It is quite likely the laser unit.

The service manual relates to the number of connectors as being different between the colour and black units. Not sure if this means separate wires or physical connectors.



Mr Stirton.M , Where do you think we should test?, Maybe LOAD. ja

RRodgers
08-19-2010, 02:28 AM
I recently went to a C500 with a laser error. Turned out it was REALLY REALLY REALLY hot in the room that it was running in. Also... the heat sync's for the lasers had TONS of dust in them. All I did was blow out the heat sync's and the machine started working again.

So, check for dust.

907tec
08-19-2010, 02:47 AM
As for my original problem here: it was solved with a new K write unit. After installing and running the calibrations, machine worked beautifully. These c6501s only LOOK intimidating, they aren't too difficult to service. Thanks for all the suggestions, guys.

jma676
08-19-2010, 02:59 AM
Anything else and finally to end with these quotes:

MPC Control - Service Manual:


Image Stabilization Control

Vm adjustment

(1) Purpose

* To achieve stabilized intermediate exposure potencial regardless of drop in sensitity of photosensitive materials or the stain of the wrinting system.

(2) Operation

* While the drums are irradiate whit a PWM128 intensity laser beam, the electric potencial on the drums are detected by the drum potencial sensor /Y (DPRS/Y), /M (DPRS/M), /C (DPRS/K). According to the detected results, the laser MPC Value is Corrected.



I hope you is not the case using the following method: Writing Init. Pos Memory ( Printer Adjustmen )

jma676
08-19-2010, 03:30 AM
back a touch of reputation

Avalon
08-19-2010, 10:19 PM
Did you set up the laser after you fitted it ? The manual does not tell you of any adjustments after replacing the laser but do a search in the service manual for the LD bias adjustment. Had to replace a magenta unit on a C6501 last month that was only 5 weeks old !

jma676
08-20-2010, 12:45 AM
Ok, so pay special attention to the installation methods

907tec
08-20-2010, 11:07 PM
yeah, definitely check out page 1757 of the SM for the calibration/setup sequence. It tells you which adjustments to do and which order to perform them, slightly different for K write unit than for CMY units. That being said, I had no problems at all with installation. Previous tech had removed the lock screw from the K write unit tilt adjust, knocking it out of alignment. Even got lucky with that one and adjusted it by eye with perfect skew afterwards.

jma676
08-20-2010, 11:53 PM
Ok I'm glad you could solve it.

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