[Misc] Sharp MX-2300N Developer Issue

[Tech2002]

There was a previous thread about the same machine and and similar issue that I am having.

I had a Developer Unit that was producing a gritty feel to the copies. When I looked at the Developer Unit, it had a clouded look to it.

I proceeded to changed the Developer - machine ran fine for a few copies - 50 or so, then reverted back to gritty feel and clouded look.

Then, I changed out the Developer Unit (Brand New) - I have seen the Developer Units go bad in this series before - not uncommon. After the Developer Unit change, everything was good, for about a month.

Last week, Wednesday, I got another call that the Black Gritty & Clouded Copies were back.

Went out to the client this morning. Checked the Bios - all within Spec.

Changed out Developer again, because I have gotten bad Developer in the past - Copies are fine again. I ran about 75 to 100 copies this time - everything looks good.

When I talked to Sharp Tech Support, there answer was to change out either the High Voltage MC PWB or the PCU PWB. I did neither of the two today because when I changed out the Developer, again, everything seemed to workout find - but again, last visit before today, I not only changed out the Deveolper Unit (Brand New), but put in fresh Deveolper, as well.

I made sure that all contacts were clean at last visit, and again today.

I am still at a loss as to where I go from here if the issue comes up again - and unfortunately, my thinking is it is going too.

Any thoughts or input would be greatly appreciated.

[Akitu]

Re: Sharp MX-2300N Developer Issue

Make sure you're doing the developer stir 25-2 after putting in new Dev so it gets the chance to initialize.

[Tech2002]

Re: Sharp MX-2300N Developer Issue

That is one thing I had not mentioned but thought it was understood that I did that - sorry for the missed information. Thanks for the thought.

[Akitu]

Re: Sharp MX-2300N Developer Issue

I've learned that if it's not mentioned, it's probably best to suggest it at any rate. I know I've missed a few simple explanations like that and it completely changes the mindset of the troubleshooting process.

[Tech2002]

Re: Sharp MX-2300N Developer Issue

Gotcha - Again, I appreciate and thank you for the thought.

[gwaddle]

Re: Sharp MX-2300N Developer Issue

Does the drum maybe have a bad spot on it and is pulling developer?

[Tech2002]

Re: Sharp MX-2300N Developer Issue

Another good point - and I left it out. I changed the Drum Unit - Brand New.

[blackcat4866]

Re: Sharp MX-2300N Developer Issue

The 'gritty' feel to the pages, and missing color, is caused by an under-toning developer. This can happen to any of the 4 developing units, either all at once or just one at a time.
The primary cause of this under-toning is a hard toner buildup over the toner density sensor inside the developing unit. This covering of the density sensor causes the PCU board to falsely detect proper toner density, and not activate the toner motors to add the much needed toner, as the sensor is reporting that there is more than enough toner inside the dev unit. This is untrue, as the actual toner density is so low, that developer passes to the drum instead of the toner, due to the toner concentration being so low.
This ongoing for too long will cause the developer to run low, as its being transferred onto the paper and scraped off the drum via the cleaning blade. When the developer itself is running low, you will notice angled toner marks at approx 45 degrees, from the dev unit augers pushing the low dev against the mag roller. You have no choice once it gets this far other than to replace the developer and start again.
The other cause of developer running low can be from an arcing main charge grid or damaged drum surface, causing developer to be pulled.
Anytime you have low developer, its always a good idea to replace drum unit & developer together, as this will rule out everything & guarantee lasting performance.

Now, are you sure its the same color developer which is under-toning? Your post does not actually mention which color is the problem. You mention that there is a black gritty feel, but when the developer is so low on toner, it actually is black due to it being iron filings etc etc.
A good way to check which color is misbehaving is to run sim 64-01. Setup A=11, B&C=2, D=255. This will give 4 large panels of CMYK halftones on the page. You will see which color is running low on toner concentration with that print. Its a very good diagnostic tool, as it clearly shows a problem on each color channel or just one. The color channel running low on toner concentration will have a marbled effect, with lots of white spots & void areas. The working units will have a nice smooth coverage.

If its the same color not working each time, and you already have a new dev unit installed, I suggest the follow be done, all in the same visit....

- Make sure the firmware is up to date
- Remove the air filters above the fuser, replace the ozone filter at the rear right corner
- Make sure the machine is at least 30cm from the rear wall, and is level
- Replace the developer & drum unit together as a set
- Run 25-02 TWICE, without restarting in between
- Run 44-27 immediately after restarting, after running developer adjust twice
- Run the ID Sensor calibration in 44-13 using the calibration jig
- Run a full color calibration 44-06, 44-26, 46-24, 67-24 & 44-06 again
Then, run a continuous test of self test print 64-05 (A=3) of at least 100-200 sets, confirming that toner density is maintained during the print run.

The above is obviously taking into account that the transfer belts are in good working order, you are using genuine Sharp toner, all settings for print & scan density are default and the optics are cleaned.

If you find that only one color channel seems to go bad on a regular basis, then install the modified process electrode covers & electrode case as per your bulletins. Any machine produced before November 2008 does not have the modified parts fitted by the factory.
If you find that all or most color channels go bad on a regular basis, then you have a temperature issue in the room, bad airflow through & around the machine, or you definitely need the updated process electrode covers installed.

If you do all of this, the problem should not/will not return. =^..^=

[hammer]

Re: Sharp MX-2300N Developer Issue

Great reply blackcat. We had this fault occurring on the cyan dev unit on an MX3500 and it turned out to be the "modified process electrode covers & electrode case".

[Tech2002]

Re: Sharp MX-2300N Developer Issue

Blackcat - that is one of the most thorough explainations that I have ever had - This is like something from wazza.

Thank you for the info - greatly appreciated. And, I appreciate Akitu & gwaddle input, as well.

I was ready to change out the MC PWB - suggested by Sharp Tech Support - But thought better of it. I got to the account and the Black DV was again bad - I changed out the DV again - ran copies and everything is fine --------- for the moment.

I will take heed of what you provided me here and see if there is still issue. The thing is the Magenta did the same thing about 6-months ago. I changed that DV and all seemed to be good.

Something unrelated but thought I'd ask - has anyone else had difficulties getting onto CopyTechNet's sight? I have tried and some days I am unable to have the server found.

[Sam Tofu]

Re: Sharp MX-2300N Developer Issue

Today is the first I've been able to access the site for 2 days. Kept getting server down notices.

I also had this happen for two or three days about 4 or 5 weeks ago.

[Tech2002]

Re: Sharp MX-2300N Developer Issue

I'm hoping this is a server issue and nothing more - This is a great place to think our issues through.

As a Tech myself, I try to learn as much as I can, but I can't know everything, and this is a good go to place
to help with doubt or confusion.

Be well -

[blackcat4866]

Re: Sharp MX-2300N Developer Issue

I was on at ~0800 EST yesterday when it dropped off and wouldn't come back. =^..^=