ES 7516AC error C471

[bryand]

Re: ES 7516AC error C471

Anyone else see ripples in the belt towards the rear side that eventually lead to the sleeve being ripped in half? We also get c472 and even a message to plug in the power cord at the rear of the machine. This error was originally from the older 6560 series with 2 power cords.

[blackcat4866]

Re: ES 7516AC error C471

I've only seen the ripples at over-yield, and I've never seen one tear in half on a Toshiba. On Kyocera, sure, the KM-8000's would be completely shredded. As long as the screws are tight on the teflon sheet and that teflon sheet doesn't get loose the sleeves seem to last.
=^..^=

[barber782]

Re: ES 7516AC error C471

Another one on the same site has got C471 now. Wtf is going on!?
Toshiba don't seem to think there's a problem.

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[blackcat4866]

Re: ES 7516AC error C471

Success with my machine, no re-occurrences. =^..^=

[Rusty.Harris]

Re: ES 7516AC error C471

Hi everyone,

Installed two Toshiba es7516ac's in a school in December 2019. After a few weeks one is getting the error code C471. Which is to do with the fuser, and turned out to be a blown thermistor.
Iv replaced the part and reassembled the fuser sleeve components with plenty of oil.
Now a month later the same error has appeared.
Does anyone know why this would keep happening? Or anyone experiencing the same on these.

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If you believe Toshiba, which I don't anymore, having dealt with this for almost 3 years, the problem is the belt holder
unit. 6LK44125000. The part number has changed 3 times, which, could be a manufacturing change, or a problem that
has been fixed, but NOT mentioned.
I have tried everything I can think of to resolve these 471 issues. More oil, different types of oil, spacers to ensure better
connections. I thought it might be a spacing problem between the fuser & the coil, so I disassembled the coil on an 08
machine that came back after being replaced. It's spring loaded, and when you latch the fuser, spacers on the coil which have
tension, align the fuser to the coil.
The tolerance of the fuse for the fuser, is "designed" to work with the 55cpm through the 85cpm machines. The fuse just isn't
up to the heat for the 85cpm machines. We don't have near the trouble with C471's in the 55, 65, 75 cpm machines in this
series, just the 85cpm machines.
It's sad too. This machine is basically a "newer" model of the 5540/5560 machines, with a different fuser. The older model
machines had fusers that would last forever. They were hard screwed into the machine. These are held with a spring latch.
I get it that they used a different mechanism to allow for a wider range of paper types, but you know that most people just
run POP...plain ole paper.
I don't know what the fix it, but I wish they would do something.

[Rusty.Harris]

Re: ES 7516AC error C471

One of the Toshiba techs I use to chit-chat with on the TABS bulletin board, until they trashed it at the first of the year,
gave me the name of a company they've been using for oil. The TABS oil always dries out.
Shin-Etsu Silicone : Fluids
I don't remember the part number, but I can get it if needed.
I've been using it for the past couple months with good success. I'm also doubling the amount, that Toshiba usually uses.

One thing we've been doing, with all of the dried out fusers, is to force the super sleep mode. Most of our 85 series machines
are in schools. They sit idle most of the time, so, to make sure they don't run all night, we set the super power saver to four
hours in the 08 codes (you can only set them to 60 minutes in admin mode) 08-9112 to 21.
If the machine sits for 4 hours, it goes to sleep, cutting the standby heating of the machine. Most of these machines they
use as printers anyway, so by the time they send the print job, go to the teachers room where the machines usually are, it
has already come out of sleep and printed the job anyway. Haven't had any complaints.
Most of our dried out fusers were late summer/early last fall. With all of the schools shut down, most of the oil just evaporated
I guess. That or the machines weren't powered off during the shutdown and just sat there running.

I have an eS8508A (basicly the same fuser) that has blown the thermostat (4) times. I put the power quality analyzer on the line but did not catch anything interesting. It usually goes for 6 weeks or more, and I didn't want to leave the analyzer sitting there for 6 weeks.

Phil: these film fusers use a thick silicone based oil (in this case OIL-965-100). We have seen cases of the inside of the sleeve drying out, taking out the fuser drive gears. That's why barber mentions using the oil generously.

I suspect power. =^..^=

[Rusty.Harris]

Re: ES 7516AC error C471

Fan speed and thermistor changes seem to be working?

Success with my machine, no re-occurrences. =^..^=

[SalesServiceGuy]

Re: ES 7516AC error C471

Another great video that I found.

Toshiba e-STUDIO 8508A, e-STUDIO 7506AC - FUSER UNIT full refurbishment

Toshiba e-STUDIO 8508A, e-STUDIO 7506AC - FUSER UNIT full refurbishment - YouTube

[barber782]

Re: ES 7516AC error C471

Mixture of firmware update and changing the thermistor and new holder etc. Never heard back after that. Also new type of oil we've been using.

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[Rusty.Harris]

Re: ES 7516AC error C471

Mixture of firmware update and changing the thermistor and new holder etc. Never heard back after that. Also new type of oil we've been using.

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A lot of the failed fusers (ripped up belts) we were seeing I think was out of habit. Most of our 85xx machines are in schools. Teachers HATE the energy saver/super sleep. We would leave the energy saver at 60 and disable super sleep. I think the supplied oil (which isn't enough) was evaporating out & the friction was just tearing them up. Since I switched to the Shin-Etu oil, and doubling the amount used, I haven't seen any dry/ripped up belts. We are still having some issues with fuses blowing & belts "melting", mostly on the non operator side of the belt. But, I think a lot of that is from the weak/failed core belt holder. Some would come back with what looks like a hot spot on one side or the other. Now that the supply chain is starting to catch up, maybe the combo of the new oil & new belt holder with the fan speed & fuser temperature settings mentioned here will start to knock down the service calls.
The amount of calls we've had on this series of machines is NOT making them profitable.

[djbass]

Re: ES 7516AC error C471

This issue was resolved in firmware version 1500 or higher that modifies some 08 codes related to temperature values, it was found due to variation in tolerance of the IH shield caused temperature to go out of the intended range.

There was also a BSI which I don't recall exactly that gave the values to change manually in earlier firmware versions.

[copytech,mike]

Re: ES 7516AC error C471

C471 has been a nightmare lately. Mostly the 85/75ppm machines. We have lowered the fuser temps with little success. Happens most often after a fuser rebuild. We have installed the new thermostat holders/covers, firmware etc. Thermostats have been on backorder for 4 weeks

Toshiba fusers are garbage and especially the thermistors. It has nothing to do with any cut off thermostat or its harness/housing. Try replacing the thermistors. You cant clean them or you will ruin them.

[Rusty.Harris]

Re: ES 7516AC error C471

Since the release of TSB-2078 Rev.02, which changed the tension of the fuser belt holder, and increased the
diameter of the mounting studs, our 471's have pretty much dropped. I started updating these around the
first of December.
When I rebuild them, I use a Sharpie to write the parts replaced and the date, along which type of lubrication
oil (stock or Shin-Etzu) and the quantity. I've cut back on the oil and now use the stock amount of either
Shin-Etzu or supplied oil (stock or Shin-Etzu). I have yet to have any of the fusers with the updated cores
come back, so they've been in the field for around 5 months, which is a RECORD! Between the updates and
the 1600 and above firmware, which changed the fuser temperatures, our problems are pretty much gone.
(knock on wood).

[pleaseteach]

Re: ES 7516AC error C471

Toshiba fusers are garbage and especially the thermistors. It has nothing to do with any cut off thermostat or its harness/housing. Try replacing the thermistors. You cant clean them or you will ruin them.

can exchange service manual toshiba with me?. brother .(conmanhahohua69@gmail.com)

[Logged-on]

Re: ES 7516AC error C471

I've had no C471 errors on the updated cores, but I've seen 2 belts fail prematurely. one at about 400k, and one at 150k. I did just discover the toner build up on the top plate just before i saw the post here about it, so I believe with the increased pressure, a little extra care with the paper guides is advised.