Canon Pro-100 - 19 ALT flashes

[fabo]

Recently attempting to resurrect a Canon Pro-100 with a B200 error. After exhausting all the usual remedies, I purchased a new 'used' print head and the B200 error ceased.
But a new error code appeared - 19 Alt flashes.
Service tool SST5103_2017 just has codes 002 and 006 that forums indicates normal if major error.
Also removed, cleaned and reattached the 3 flex cables in the head - cartridge assembly

Problem seems to trigger after start purge: head moves left, does a LED dance back-forth and few times then alt 19 orange-white flash.
Checked the QM7-1442 board and the sensor board below - nothing obvious.
Installed a new 3rd party set of cartridges - All carts light up
During startup , if cover sensor is open , maintenance mode in printer properties responds and waits at printer center with opr message ' Cartridge refill' zone .
when sensor is closed, start-up continues, errors out and then printer properties also shows fatal error..
Also placed original print head back in printer with same results.

The prints (when working) were outstanding and really relied on the large format printing.,
Getting ready to scrap this out and get a Canon Pro-200 or 200S

Not sure what the printer is doing when it checks each cart multiple times,
but recall its the the same original fatal error -maybe the sensor below or on the QM7-1442 board.

 

[PeterBJ]

I don't know which service tool version is needed for the Pro 100. The use of a too old (too low version number) service tool will block access to service mode. Error 002 indicates a function not supported by the printer was attempted and Error 006 indicated the printer has not entered service mode.

The 19 alternate flashes indicates a problem with a cartridge not being recognised by the printer. Here is a list of Canon error messages from druckerchannel.de. You can use google translate or other translator if you don't read German.

Here is the 19 alternate flashes translated to English:

or from the Pro 9000 mkII service manual:

When the printer is powered on the cartridges are checked by passing the printhead under a photocell sensor that checks for the red light from the chips. This means there could be a problem with the sensor, a chip or the chip contact springs. See this post for a photo of chip contact springs.

There are no service manuals available for the Pro 100, but see this post about an older printer and the ink cartridge sensor.

As all the cartridges light up there seems to be no problems with the chips and the chip contact springs. But i have had a defective chip on a CLI-8 M cartridge that would light up when the printer was opened, but could not be recognised. With another CLI-8M cartridge installed the problem was gone.

I think the problem is caused by either the cartridge sensor or a defective chip. You could try to install the old cartridges again. Even if they might be empty they should not prevent the start up of the printer. You would of course get an error message about empty carts.

 

[fabo]

thanks for the help.
Having the error code pointing to the ink tank position, helped alot to focus on the two sensor boards.
The bottom sensor PCB (QM7-1443) appears to be a reflective IR sensor for ink tank position(?).
The side Sensor PCB (QM7-1442) contains a thermistor and 3 pin optical device for cartridge ink level.

With the printer in operational mode (PS at 32V), no supply voltages on either board traced back to flex cable on front panel using an o-scope..

Won't put any more money to repair but will disassemble and check main board.
No schematics, but maybe there is a common fail point like a regulator circuit that supplies the sensor boards.

 

[PeterBJ]

The bottom sensor is a reflection sensor and scans the prisms in the bottom of the cartridges' ink compartment. When the prism is covered in ink the prism is non reflective. When the prism is no longer covered in ink the prism becomes reflective and the sensor triggers a warning that the cartridge will soon be empty.

This post has a photo of an iP4200 logic board. I think the ferrite inductors and electrolytic capacitors at the right edge of the print are parts of voltage regulators for the 3,3 V and 5 V logic and USB voltages.

Maybe a short circuit somewhere causes the 3.3 V regulator to shut down?

A wild guess: The previous owner cleaned the printhead under running water and installed it before it was dry. Leakage from the 32 V nozzle driver voltage leaked into the 3.3 V logic circuits and caused damage.

Edit: The chips and chip LEDs must also be powered by 3.3 V as many resetters are powered by a single CR2032 cell. At reset the LED lights at normal intensity. So the 3.3 V regulator seems to be working, and at least some parts of the 3.3 V logic are powered as the chip LEDs light up.

 

[fabo]

I did extensive checking and circuit tracing of the bottom sensor. While in operation, the is no voltage supplied the to the bottom sensor. The output floats to 3.3V but no change if the sensor LED is not active.
Removed the main board and traced out the sensor signals. There is a 6 pin NPN-PNP switch that is controlled by the CPU. The switch (marked D35') is fed by 3.3V, the the PS rail looks ok. In operation, the signal from the CPU to the switch to the bottom sensor does not change indicating it is a CPU issue not a PS, switch or sensor.
I added some test leads around the switch and, after placing the board back in the printer, monitored the circuit to confirm the CPU is not activating the sensor and power supply is active and clean .

I wasn't sure if the sensor was working so I cut the LED line to the sensor and put some steady current on the sensor. With the printer powered up and the sensor output floating to 3.3V, no output change when the printer head was moved back and forth over the sensor. Expected something if sensor was functional.

Now the mystery: I removed the sensor board and did some testing in controlled conditions on the bench.
Confirmed the sensor output did not change when a card, finger or metal was placed over or near the sensor.
However, using a functional sensor (not the same type) from another canon printer teardown, I could get the Pro-100 sensor output to change when the other sensor was ON and illuminating the Pro-100 sensor. The other sensor also changed when the Pro-100 illuminated the other sensor.

It is my printer purchased in 2017 with not many hours on it. No spilled ink, condition was pristine.

Unless there is some other condition that causes the CPU not to activate the sensor (or my analysis was misguided),
I would conclude an issue with the CPU and attempt to reload a new firmware image.
Not sure if the FW can be loaded if the printer is an error state but will try.