Konica-Minolta 8050 SC35-02

[Beachguy]

I keep getting this code periodically. I know how to reset it but I was wondering if anybody had any ideas on why it keeps coming back. (usually about once a month).

Thanks

[brian155]

I had this same problem a while ago and it turned out to be the fuser drive motor page 40 part number 1. 56AA 8007 2 DC BRUSHLESS MOTOR 30
Before this i tried all the usual rollers/lamps/thermisters etc.

[rockin57rod]

I have the same problem....I was thinking of trying the ACDB board....

[Coptech]

Have an 8050 that did this at around 3M copies. Tech support had me replace every board in the machine with no positive results. I had changed all the temp sensors. Konica senta rep that expected I would have a lamp in backwards. I never found the problem. Replaced entire fuser and problem solved for a few years. When it started again after 4-5M more copies, I replaced the contact thermistors and problem gone. Bottom line is that I believe the problem is in the fuser but not certain where. This one would happen a few times a day though and then maybe have a couple of good weeks.

[Stirton.M]

A TSB on the subject...

Subject:
SC35-02.
Description:
SC35-02.
Solution:
CAUSE: Fixing low temperature abnormality (TH2). Fixing temperature sensor/1 (TH2) deduction temperature less than 150 degrees C was continuously detected.

SOLUTION: The temperature sensor (p/n 65AA-5540) that comes in contact with the upper fuser roller was pushed away from the roller. Reform the sensor against the roller and reset software dipswitch 3-1 to 0.

[Coptech]

Pretty common that the contact thermistors can be bent away from the rollers while replacing rollers. I always made sure they were still in contact and had to clean the white powder that comes from coated paper stock. I like the drive motor idea as that fits within the entire fuser scope and did not get replaced before the fusing unit exchange.

[rockin57rod]

The thing that gets me is that everything in the fuser checks out...but the machine thinks the lower heat roller has gone cold. The operator also claims there are some fusing issues...so that makes me think it's not a noise problem...it is actually dropping in temperature. So I figure it's either the lamp not coming on...or the temp sensor. I chased everything back to the ACDB PWb and that has those tacky electro-mechanical relays on it ( just like the EP-300 toner motor relay) ...so I figure it may be the contacts in the relay starting to die....but I'm open for suggestions

[Stirton.M]

The thing that gets me is that everything in the fuser checks out...but the machine thinks the lower heat roller has gone cold. The operator also claims there are some fusing issues...so that makes me think it's not a noise problem...it is actually dropping in temperature. So I figure it's either the lamp not coming on...or the temp sensor. I chased everything back to the ACDB PWb and that has those tacky electro-mechanical relays on it ( just like the EP-300 toner motor relay) ...so I figure it may be the contacts in the relay starting to die....but I'm open for suggestions

There is no lamp in the lower roller, so the only source would be the lamps on the upper roller. Perhaps the problem is more mechanical, that you are not attaining proper fuser pressure, last I looked, this was the only way for the lower roller to get any heat.

Through the Output Check in tech rep, you can test if the fuser pressure is being properly applied. Perhaps the flag for the sensor is damaged and not sitting in the correct position so when the motor reverses to apply pressure, the sensor is being triggered prematurely. See attached image, I underlined the sensor flag in question.

It couldn't hurt to look at the torque limiter too...

[rockin57rod]

Thanks for the input..I owe you one....I'll check it out next week...

[Coptech]

There is a fusing lamp in the lower roller. If there isn't you may have found a problem. Trust me. I have PM'd an 8050 in a print shop over 75 times during it's life and I can say with no doubt that there is a lamp going through the center of the press roller. 2 in the upper fusing roller.

[rockin57rod]

Your right coptech....but when someone is nice enough to help you online...it's only polite not to nit pick at the details...

[Stirton.M]

There is a fusing lamp in the lower roller. If there isn't you may have found a problem. Trust me. I have PM'd an 8050 in a print shop over 75 times during it's life and I can say with no doubt that there is a lamp going through the center of the press roller. 2 in the upper fusing roller.

You are right...I was looking at the lower roller and not seeing the lamp....but when you mentioned it, I took another look and sure enough...it's a bit misleading in the image, I thought it was one of those round bars. It's been some time since I looked at an 8050

Then from that, to verify if the heat lamp is coming on, take the front cover off, cheat the front door and observe the fuser during the warmup phase...all the heat lamps should be lit.

[rockin57rod]

Thanks for the input. I've checked the lamps and all the other components...the problem is very intermittent....I figure I'll just have to start swapping components out or keep looking for a silver bullet. I only see this machine once a week, and I now have some good tips to follow...If it was a Xerox...I could eureka the problem.....LOL.....I guess no good deed goes unpunished.

[Coptech]

The machine I have dealt with would give fusing codes in the middle of a run. It never seemed to be the same code. It may be overheat or underheat. I never saw fusing problems that showed up on the copies. It was frustrating to the customer because it loses count with a fusing code.

Looking at the code, it is TH2 lower fusing roller non contact sensor low temp which is the emphor red sensor in the middle of the fuser below the lower roller. Is there any chance that it could have some dust inside it as they are somewhat hollow. Other than that, I would check the wiring from it.

I did not mean any "smart ass" in my previous post and certainly hope that it was not percieved that way. I am sorry if it did come across that way at all.

[Stirton.M]

I did not mean any "smart ass" in my previous post and certainly hope that it was not percieved that way. I am sorry if it did come across that way at all.

Not at all. I should have been paying a bit closer attention to the parts diagram when I was viewing it.

Somewhere along the line, I remember another machine that doesn't have a lamp in the lower roller...maybe I am mixing that one up with this one.