Konica Minolta C308 - Cyan issue

[Kenny]

Cyan develpoing unit is new and if there is developer on magnet roller and just toner is missing there is no need to replace it again.

I would try with a new ( or used ) drum YMC and run TCR manual add for cyan and "image stabilization only". After stabilization check VDC-C and VG-C if they are back to normal.

After that pull out dev unit c and ckeck if magnet roller turned cyan i.e. holding cyan toner on itself.

If not I would use HV board from other machine and see if that get satisfactory result.

Again run TCR manual add for cyan to rotate dev unit (cyan toner must fill magnet roller) and "image stabilization only" to correct the values.

After you find problematic component, order and replace a new one.

i have tried the above, but still not got it working.

here's what i have tried:

- tried a HV board from another machine it didn't change the levels and the cyan dev is still black

- tried a used dev and drums from another machine, the dev has once again turned black? i also tried a new dev and drum but still no avail.

- i have pulled out the main drive and checked if the air ports where full, they wasn't.

- checked the toners bottles are turning

- i cannot see what is over life as for some reason all the consumables have been reset the machine has only done 150k

- i have pulled out the toner hopper to see if it clogged/blocked but looks fine.

dont really know where to go from here

[femaster]

Have you confirmed that the shutter on the bottom of the hopper assembly is opening when the dev unit is inserted?
Have you verified that the hopper is actually turning and attempting to add toner to the dev unit?

Easiest way to know for sure if it trying to add is to pull the output tray cover off from above the toner bottles, run the manual toner add for cyan, and watch the metal shaft/gears that is closest to the exit of the copier. This is the shaft that should turn when the hopper is adding toner to the cyan dev unit. See silver metal shafts in included picture. The shafts are positioned so that they are in between the toner bottles. If needed, remove the Cyan and Black toners for easier viewing.
C308 Hopper Unit.jpg

[kingarthur]

Hi guys,

i have just turned the machine on checked the levels

Attachment 49827

VDC-C is 800
VG-C is 950

This is probably caused by one of the other colours being "over life"

[Kenny]

Have you confirmed that the shutter on the bottom of the hopper assembly is opening when the dev unit is inserted?
Have you verified that the hopper is actually turning and attempting to add toner to the dev unit?

Easiest way to know for sure if it trying to add is to pull the output tray cover off from above the toner bottles, run the manual toner add for cyan, and watch the metal shaft/gears that is closest to the exit of the copier. This is the shaft that should turn when the hopper is adding toner to the cyan dev unit. See silver metal shafts in included picture. The shafts are positioned so that they are in between the toner bottles. If needed, remove the Cyan and Black toners for easier viewing.
C308 Hopper Unit.jpg

i have checked the shutter and is opening when inserting the dev unit,

i have performed the manual toner add and the metal shafts do not rotate, i have checked on a working C308 in the office and those metal shafts don't move either?

[REGSIS]

dont really know where to go from here

Huh! This is wild!
Try Front side board FSB (behind waste toner box) and Power supply board (on the left side).

Is Magnet roller turning cyan if you turn dev unit C manually?
If yes mark the white gears on the back end to check if they are turning.
There should be only one clutch for CMY (at least it is on 4 series), so that shouldn't be the problem, but just in case.

Are you running manual TCR and image stabilization + checking the voltage values after each attemp?

[Gift]

I had a one timer when one of the toner bottles didn't turn so the machine couldn't add toner. Still it should recognize this before there is no toner in the dev mix.

Is the mag roller evenly coated with dev or is there a diagonal/zebra-ish pattern visible?

[Kenny]

Huh! This is wild!
Try Front side board FSB (behind waste toner box) and Power supply board (on the left side).

Is Magnet roller turning cyan if you turn dev unit C manually?
If yes mark the white gears on the back end to check if they are turning.
There should be only one clutch for CMY (at least it is on 4 series), so that shouldn't be the problem, but just in case.

Are you running manual TCR and image stabilization + checking the voltage values after each attemp?

no when i turn it manually there is no cyan there.

and yes i am running that but the table numbers wont budge, i think this machine just hates me

i have now tried replacing the hopper unit, front relay board and the power supply board

[Kenny]

I had a one timer when one of the toner bottles didn't turn so the machine couldn't add toner. Still it should recognize this before there is no toner in the dev mix.

Is the mag roller evenly coated with dev or is there a diagonal/zebra-ish pattern visible?

ive checked and the toner bottles do turn, ive pulled the dev unit out and its all even with black developer

[tsbservice]

Just a wild guess. Maybe it's black developer unit mistaken with Cyan dev. unit
Can you run 50 cyan halftone patterns at 255 density?

[REGSIS]

- i have pulled out the main drive and checked if the air ports where full, they wasn't.

Have you check gears on main drive unit which drive the cyan dev unit?

I don't understand how don't you get toner on magnet roller if you turn it manually and your TCR is 6-7%.
There should be plenty of toner inside.

Toner hopper is ok if that TCR ratio is real.
Front side board could possibly show false TCR ratio and toner is not added anymore.