Bizhub C454e with K Imaging issues

[JasonSBE]

This is an odd one for me. Customer put in service request stating that machine was giving them poor image quality. I had them print the built-in demo page and send an image to me. The black portion of the image was not being put on the paper, instead there was some residue on the page that looked like developer. I grabbed a brand new IU-512K and DR-512k and went to the site. TCR density for CMY were all in the expected range, but K was a 0.00%. Replaced the drum and developer as a set(Drum was at end of life, and I've seen issues where these machines will bleed out a developer if you have an old drum, so I figured it was worth doing). Printed some test patterns, and the image was very light. TCR density read normal.

I decided to take the machine back to my shop to work on it. First thing I did was try another developing unit. This time I pulled one out of another machine. Print quality was good, but TCR density showed very high.... like almost 19%. Naturally, the machine coded out every 20 pages or so. I ran some full density half tones to see if the level would drop and the machine would level out, but by the time the TCR sensor was detecting density down to around 12% copy quality was awful. Next thing I tried was changing out the board the developers plug into(A7PUH00500 FRB Board). Flashed the firmware to latest base, and still having the same issues.

Never seen anything like this issue, was hoping for some insite.

[techsxge]

Re: Bizhub C454e with K Imaging issues

This is an odd one for me. Customer put in service request stating that machine was giving them poor image quality. I had them print the built-in demo page and send an image to me. The black portion of the image was not being put on the paper, instead there was some residue on the page that looked like developer. I grabbed a brand new IU-512K and DR-512k and went to the site. TCR density for CMY were all in the expected range, but K was a 0.00%. Replaced the drum and developer as a set(Drum was at end of life, and I've seen issues where these machines will bleed out a developer if you have an old drum, so I figured it was worth doing). Printed some test patterns, and the image was very light. TCR density read normal.

I decided to take the machine back to my shop to work on it. First thing I did was try another developing unit. This time I pulled one out of another machine. Print quality was good, but TCR density showed very high.... like almost 19%. Naturally, the machine coded out every 20 pages or so. I ran some full density half tones to see if the level would drop and the machine would level out, but by the time the TCR sensor was detecting density down to around 12% copy quality was awful. Next thing I tried was changing out the board the developers plug into(A7PUH00500 FRB Board). Flashed the firmware to latest base, and still having the same issues.

Never seen anything like this issue, was hoping for some insite.

If you stop the machine mid-rpint, can you get a perfectly fine image on the transfer belt unit?
If not, then your issue might be the toner itself (Aftermarket?) not being able to be fixed by the fusing unit. If it is bad there already, then you might just have a feeding problem

[techsxge]

Re: Bizhub C454e with K Imaging issues

Thinking about it before i wanted to sleep, this sounds more like an issue with the PH / Laser Unit. I'd just replace it to be honest

[Woxner]

Re: Bizhub C454e with K Imaging issues

replace the hv pwb known to cause this. also ck transfer belt to make sure roller is not broken (end joint) i have seen these not touch the drum. are you gettin the banding from dev unit.

[JasonSBE]

Re: Bizhub C454e with K Imaging issues

I tried replacing the HV board shortly after making this post. No change. I don't think it's the transfer belt because when I put the used developer unit in the machine(when it showed 19% density in the state confirmation tcr history) the image was actually quite normal. Once the level started to drop closer to the normal range, the image gradually got lighter and lighter. For this reason I don't think it could be the PH, either.


Edit:

After replacing the HV board, I also changed the Printer control board. Same result.

[Synthohol]

Re: Bizhub C454e with K Imaging issues

check the transfer belt like Woxner suggested.

[JasonSBE]

Re: Bizhub C454e with K Imaging issues

I'm not sure how the transfer belt would cause the TCR sensor to show such a high reading in the developing unit but I will check it 1st thing whenever I get to the office in the morning. Thanks. Any other suggestions for anyone?

[copyman]

Re: Bizhub C454e with K Imaging issues

Really strange all of a sudden there are weird quality issues. 2 machines in same week showing "0"% toner levels. All the 4 series I've worked on and maybe seen it one time. I've seen the level history low when dev dumped but never "0" !! Is it coincidental this is happening since the Kon/Min toner shortage and having no choice but to use aftermarket toners? Or even if genuine toners did Kon/Min have to resort to using crap toner? Something just doesn't add up with all these weird quality issues!!!

[JasonSBE]

Re: Bizhub C454e with K Imaging issues

Really strange all of a sudden there are weird quality issues. 2 machines in same week showing "0"% toner levels. All the 4 series I've worked on and maybe seen it one time. I've seen the level history low when dev dumped but never "0" !! Is it coincidental this is happening since the Kon/Min toner shortage and having no choice but to use aftermarket toners? Or even if genuine toners did Kon/Min have to resort to using crap toner? Something just doesn't add up with all these weird quality issues!!!

I thought about that too because we have had to buy some non-oem toners to deal with supply chain issues, and I saw said toners decimate another c454e we had on the field, but this machine is very low volume of use, and all the toners in it were OEM from before the shortages. I should also note that right before I shut down for the day I tried swapping out the toner subhopper assembly just in case it wasn't replenishing properly. Didn't change anything.

[tsbservice]

Re: Bizhub C454e with K Imaging issues

I thought about that too because we have had to buy some non-oem toners to deal with supply chain issues, and I saw said toners decimate another c454e we had on the field, but this machine is very low volume of use, and all the toners in it were OEM from before the shortages. I should also note that right before I shut down for the day I tried swapping out the toner subhopper assembly just in case it wasn't replenishing properly. Didn't change anything.

I'm afraid at this situation you may be pointing at MFPB replacement..

[tmmdmmm]

Re: Bizhub C454e with K Imaging issues

How is the hopper working? I stupidly forgot to plug in the K motor after replacing a fan and within 2 days got a call for 2557, TCR 0.00. Plugged the motor back in and manual add toner, brought it up to normal.
The front board is detecting TCR, proven by the replacement dev (although it was abnormally high) and you already ruled out the HV

[JasonSBE]

Re: Bizhub C454e with K Imaging issues

Wasn't the transfer belt. Wasn't the MFP board. Already tried replacing the sub-hopper. I'm just about out of ideas at this point. Don't really feel like I'm troubleshooting, just throwing parts at the problem. Not a fan of that philosophy.

[techsxge]

Re: Bizhub C454e with K Imaging issues

Wasn't the transfer belt. Wasn't the MFP board. Already tried replacing the sub-hopper. I'm just about out of ideas at this point. Don't really feel like I'm troubleshooting, just throwing parts at the problem. Not a fan of that philosophy.

Have you cleaned the machine out of toner and tried a different toner bottle?
Check if the image is fine on the transfer belt when interrupting the print process. Usually about half a second after you hear the machine taking out paper from tray you just open front lid or side lid and then take out transfer belt. Given that you already changed the transfer belt, it could be the transfer roll or the fusing unit.


Could we maybe get a picture of the printed image?

[tmmdmmm]

Re: Bizhub C454e with K Imaging issues

Have you cleaned the machine out of toner and tried a different toner bottle?
Check if the image is fine on the transfer belt when interrupting the print process. Usually about half a second after you hear the machine taking out paper from tray you just open front lid or side lid and then take out transfer belt. Given that you already changed the transfer belt, it could be the transfer roll or the fusing unit.

Don't think so, if its only affecting K and the TCR is all out of whack I can't see it being anything belt or after. With imaging; Toner, Hopper/Motor, Dev, Drum. You ruled all 4 of those out. With electrical Dev, FRB, Printer Control Board, harness between them.
TCR Sensor K is CN13 on the FRB, but doesn't have a specific out to the PRCB. CN3 does include DV_K_Detect which goes to CN9 on the PRCB.

I would say PRCB, but 1) you already tried it and 2) it doesn't seem like a detection issue. That does leave imaging. As @techsxge mentioned it could also be unrelated to the developer being refilled. PH, hvb.

You've hit literally all of these marks short of specifically saying whether or not you stabngrad or checked the IDC sensors, and you mentioned toner was OEM.

I'm stumped.....

A scan of Demo page and CMYK halftones at 111 and 255 might shed some light, but I think you explained it well enough.

[tsbservice]

Re: Bizhub C454e with K Imaging issues

Wasn't the transfer belt. Wasn't the MFP board. Already tried replacing the sub-hopper. I'm just about out of ideas at this point. Don't really feel like I'm troubleshooting, just throwing parts at the problem. Not a fan of that philosophy.

Absolutely. You've changed everything but pulling the trigger until you run out of bullets isn't really good troubleshooting. Like tmmdmmm said we're stumped but nevertheless never give up.
At this point I would distance from throwing parts into machine and start from the beginning - theory of operation is good starting point. I'm positive you will resolve it