Got from Chinaman.......

[Hansoon]

...... NO, not egg noodles but a set of thermistors for the BH-C-280/360 series.

I had to rebuild the fuser since it made over 600K. The original thermistors where covered with brown goo, so to make it perfect I also replaced the 4 thermistors with non-OEM from Chinaman.

Shortly after firing up the machine it gave me a C-3721 service code for overheating accompanied with a stench of overheated plastic.

After inspecting the fuser unit I found following:

ThermistorChina 20210123_163802.jpg
(The violet paint our company uses to mark NON-OEM parts.)

Since this is my own office machine and I did not want to invest in a new fuser unit, at the same time not having a replacement for the thermistors I compared the thermistors of the BH-C-280/360 series with those of the ancient BH-C-353 machines, from which I have many to scrap, and they have the same electrical specs of 1.6MOhm at room temperature. They are mechanically totally different but I managed to adapt them. Trusting that, keeping them from the surface a millimeter, like in the the original C-280/360 and not like in the C-353, where they are touching the surface of the fuser foil it would work and yes it did. (keeping for the coming hours fingers crossed and having the # of the fire squad at hand, I think its OK) Allright, it looks clunky but it works and didn't cost me a dime.....

20210123_151717.jpg

20210123_151653.jpg

Hans

[blackcat4866]

The clunky aspect doesn't bother me as long as it fits inside the fuser cover. Nice work!

I've been trying to figure out diagnosing some Toshiba thermistors. My latest method is to warm up the clothes iron set to "Cotton". I pressed the thermistor to the tip of the iron and read resistance across a low 150C to high range 180C (a clothes iron cycles off/on just like a fuser giving a standard range of values). So a good thermister reads from <7.3Ω @ 150C to <5.6Ω @ 180C. At least with Toshiba themistors I used to read room temperature ~400KΩ and finger temperature ~270KΩ, which is not predictive of whether your thermistor is good or not.

That's just disappointing that you Chinese thermistors clearly were never tested in a real fusing unit. =^..^=

[BillyCarpenter]

The clunky aspect doesn't bother me as long as it fits inside the fuser cover. Nice work!

I've been trying to figure out diagnosing some Toshiba thermistors. My latest method is to warm up the clothes iron set to "Cotton". I pressed the thermistor to the tip of the iron and read resistance across a low 150C to high range 180C (a clothes iron cycles off/on just like a fuser giving a standard range of values). So a good thermister reads from <7.3Ω @ 150C to <5.6Ω @ 180C. At least with Toshiba themistors I used to read room temperature ~400KΩ and finger temperature ~270KΩ, which is not predictive of whether your thermistor is good or not.

That's just disappointing that you Chinese thermistors clearly were never tested in a real fusing unit. =^..^=

I've done some crazy shit like that in the past to test a thermistor. I thought I was the only one. lol


I think I used a soldering iron.

[allan]

Good job on getting your office machine running with your mod.

On the 223/423 machines the 3de party NTC's works real well and does not scratch the upper like the original ones. But sure you know that. Wonder if they are in the same resistance range?

Those are chines...

[Hansoon]

Good job on getting your office machine running with your mod.

On the 223/423 machines the 3de party NTC's works real well and does not scratch the upper like the original ones. But sure you know that. Wonder if they are in the same resistance range?

Those are chines...

Yes Allan, They are exactly the same 1.6MOhm at room temperature. But in the BH363/423 series no need to replace them most of the time. I just cover them with Teflon tape and than they, together with our modified Teflon hot rollers, live both together for ages....

Hans

[Hansoon]

"The clunky aspect doesn't bother me as long as it fits inside the fuser cover."

The black plastic cover fits snugly. No signs on the outside, nobody will know the fuser has been "tampered" with.

The blue goo is heat resistant silicone compound keeping the thermistor housing from turning around the single screw. I felt too lazy to drill another hole beside it. It's Saturday today you know.....

Checking the temperature constantly in "State Confirmation" the temperature of the UFR fluctuates between 176-189°C and the LFR 145-150 °C

Hans

[mascan42]

They made those thermistors while making peepee in your Coke.

[copier tech]

...... NO, not egg noodles but a set of thermistors for the BH-C-280/360 series.

I had to rebuild the fuser since it made over 600K. The original thermistors where covered with brown goo, so to make it perfect I also replaced the 4 thermistors with non-OEM from Chinaman.

Shortly after firing up the machine it gave me a C-3721 service code for overheating accompanied with a stench of overheated plastic.

After inspecting the fuser unit I found following:

ThermistorChina 20210123_163802.jpg
(The violet paint our company uses to mark NON-OEM parts.)

Since this is my own office machine and I did not want to invest in a new fuser unit, at the same time not having a replacement for the thermistors I compared the thermistors of the BH-C-280/360 series with those of the ancient BH-C-353 machines, from which I have many to scrap, and they have the same electrical specs of 1.6MOhm at room temperature. They are mechanically totally different but I managed to adapt them. Trusting that, keeping them from the surface a millimeter, like in the the original C-280/360 and not like in the C-353, where they are touching the surface of the fuser foil it would work and yes it did. (keeping for the coming hours fingers crossed and having the # of the fire squad at hand, I think its OK) Allright, it looks clunky but it works and didn't cost me a dime.....

20210123_151717.jpg

20210123_151653.jpg

Hans

Wow this would be serious breach of health & safely here in the UK, you can smell burning on a fuser that has done 600k after replacing parts from an unknown source.

Don't EVER leave that machine on unattended

[Hansoon]

Wow this would be serious breach of health & safely here in the UK, you can smell burning on a fuser that has done 600k after replacing parts from an unknown source.

Don't EVER leave that machine on unattended

Don't get it. The risk seems theoretical to me.

The fuser made 600K. Than it was rebuild with: new UFR, new fuser film, new foam roller, new LFR, new bearings where necessary. This is our standard procedure since years and works well. The exception now was that the thermistors seemed OK but where extremely dirty covered with brown goo, hard to clean. Therefore I took those china-man thermistors from an me unknown supplier in AliBaba. Never used AliBaba before and they f§§ed me obviously.

The risk of causing havoc seems rather small to me since there is always the thermal cut out in the fuser. The thermal cutout not even opened this time, the machines logic was quicker in erroring out with C-3721.

OK, me too will feel happier having this machine for our own use in the office only. I would never put it outside with our clients. Though the C-353 thermistors I used now have the same electrical resistance at room temperature and also at 185°C, I do not know if their reaction curve is the same and perhaps there are other parameters than those two such as tolerance and how swift they react on temperature differences.

I'm not afraid to sit beside the beast anyway.......

Hans

[copier tech]

Don't get it. The risk seems theoretical to me.

The fuser made 600K. Than it was rebuild with: new UFR, new fuser film, new foam roller, new LFR, new bearings where necessary. This is our standard procedure since years and works well. The exception now was that the thermistors seemed OK but where extremely dirty covered with brown goo, hard to clean. Therefore I took those china-man thermistors from an me unknown supplier in AliBaba. Never used AliBaba before and they f§§ed me obviously.

The risk of causing havoc seems rather small to me since there is always the thermal cut out in the fuser. The thermal cutout not even opened this time, the machines logic was quicker in erroring out with C-3721.

OK, me too will feel happier having this machine for our own use in the office only. I would never put it outside with our clients. Though the C-353 thermistors I used now have the same electrical resistance at room temperature and also at 185°C, I do not know if their reaction curve is the same and perhaps there are other parameters than those two such as tolerance and how swift they react on temperature differences.

I'm not afraid to sit beside the beast anyway.......

Hans

The fact you stated the machine 'made a stench of overheated plastic' would ring alarm bells with me.

Konica Minolta didn't design these fusers to be rebuilt after 600k it owes you nothing, personally I would replace the fuser with a new one & get another 600k trouble free printing.

But I do understand some techs are working in poverty so have to do what they can.