Phaser 850 15,003 Error, freezes in diag mode

[iqd]

Hello !

When i boot the printer the error 15,003 shows up.
But an error 15,004 never did.

It appears sometimes at 57% warmup time, sometimes 89% etc.
I checked the halogen bulbs, which are both ok.
I also cleaned the temperature sensor and measured it's
thermal resistance (decreases/increases at heating/cooling), so it seems okay.

If i set the #1 DIP switch and reset/power on the printer the green and the red light on the front panel are on.
But the display is off, no light, no text(even after 20 minutes).

If i use the DIP #1 when the printer is running and DIP #4 to reset it, the same (the display freezes).
It also does not heat or something else.

Does the 850 has another DIP setting for the diag mode?

Any solutions?

Many thanks.
Harald

 

[Dacurve]

15.003.44 - From the service manual:

The drum heater is running away. Unplug the printer NOW!
Verify that the vent on the right side of the printer is not blocked.
Ensure that the drum fan rotates and is installed correctly.

840 & 850 do not have internal diagnostics like the 860 & 8200. You'll need the pc diagnostics software for these machines.

 

[iqd]

Thank you !

I checked the fan and it works.
As i have not the diagnostic software (and cable), i cannot monitor the sensors.

I measured the drum temperature sensor and it has ~220kOhms at room temperature but i falls to ~30kOhms within 3 seconds.

Does this mean it is defective or is this big decreasing normal? Has someone the exact data for this sensor so i can replace it?

Perhaps someone has the mentioned diagnostic software. I also read a thread on the pin outs for the diagnostic cable. Does a finsihed schematic print now exists?

 

[Dacurve]

When you look on right the side of the machine through the ventilation holes, you should see the bulbs in the preheater flashing. -Are- they flashing, or are they on solid?
I have had this once with a similar machine, one of the triac's on the power supply was faulty and causing the bulb to be on solid -> causing overheating and this error.

I am not sure about the resistance of the drum temp sensor, sorry.

 

[iqd]

The bulbs are flashing.
I found out that the sensor is working correctly.
Seems that the printhead overheats the drum.
If i disconnect the printhead (heating etc.) the drum is heated to it's operating temperature. (even can touch it with the hand for short time).
The fan is also slowing down and goes off at the end.

If i reconnect the printhead it overheats the drum (its as nearly as hot as the printhead) and then the drum temperature sensor triggers 15,003.44 -> TCD_THERMISTOR_HOT and the fan is rotating at full speed.
The resin sticks are melted and are liquid as water before the error is triggered but it seems that the printhead is still heating.

I am trying to check the Thermistor on the bottom of the printhead.
Cause the drum-printhead gap cannot be adjusted as on the 840 i guess the printhead thermistor is faulty.

Or is it possible that the drum-printhead gap is to small and the drum acts as a heatsink as described for the 840?

 

[marty5261]

The printhead can be adjusted for head to drum spacing, from the 850s on they set this at the factory. The adjustment is the same if you are experiencing problems related to the spacing. As far as the sensor resistance readings I have only seen one bad drum temp sensor and when I put a meter to it , it was wide open, I am unsure what the normal readings should be.

 

[Dacurve]

Do you have access to a service manual, or do you know how to adjust the printhead-to-drum spacing?
It shouldn't be needed on the 850 or later models, but it might be worth the try.

I know that just the heat of the printhead is enough to keep the drum on temperature, without the paper preheater (once it's on operating temperature).
So I suppose, when the printhead is too close to the drum. The drum could act like a heatsink and draw heat from the printhead.
However, my experience is that if the head to drum gap is too small. You will get a 13,004.43 or 13,020.41 error (jetstack heaters heating too slow).

Perhaps a power supply problem. Or did you ever replace the lamps in the preheater?

 

[iqd]

Hooray, i solved the problems and the printer does it's job again

I received some service manuals yesterday (840,850,860 models).

Here is what i did (the problems) if you are interested in:

Preheater lamps did not worked at my first posting: the connectors were corroded.

I disassembled the whole printer today and was really "shocked".

First the printhead connector crumbled between my fingers. Changed it.
Someone (perhaps the guy i have the printer from) tilted the printer while running. There was a 5mm resin crust at the bottom of the whole printhead and on the orange/red circuit flat cable.

And HERE were the problems that caused overheating:
The printhead thermistor was covered with the 5mm resin crust and the printhead-drum gap was much to close.

There even was some scratching from the drum on the printhead (seems the printhead touched the drum a while ago, but surprisingly the drum had no scratching at all; perhaps xerox replaced this thing).

Cleaned, reassembled the printer and adjusted the printhead-drum gap.
Prints fine (even the printhead-drum gap is now perfectly adjusted).
Apart from smears and "scratches" (which i am confident to fix) it prints sharp and nice.

It is really incomprehensive how some people treat their printers.

Than you all very much for your quick help and support.
Best regards, Harald.