Print head fault in Pixma iP7260

[mikeg]

I have two Canon printers, an iP7260 and an MG5660. Both use refilled PGI-650/651XL cartridges.
Recently the 7260 stopped working with error message of 5 orange flashes, (Print head not installed. Print head not installed correctly. Print head is defective).
On calling Canon Australia, I was advised to contact a service center (the closest is 160 miles away) and they advised over the phone to buy a new printer.
If I try to print, the software gives an on-screen message "error code 1403" which a further internet search indicates a failure of the print head thermal sensor.
I have carried out all the usual functions, cleaned the print head, exchanged the cartridges with my MG5660 and even removed and examined the print head carriage, all without success.
Can anyone suggest where the thermal sensor is located (if it exists) or perhaps someone has a pin-out diagram for the print head so I could try bypassing the fault signal.
Any advice would be appreciated as I believe the old girl still has some life left in her and I have a number of refillable cartridges and chip resetters which don't suit any of the new model Canon printers..
Cheers,
Mikeg

 

[PeterBJ]

The print head is a large special integrated circuit. Temperature is measured by diodes on the printhead substrate, as the characteristics of a diode are temperature dependent.

This post suggests that some have "repaired" an overheating printhead by cutting the connections to the internal diodes and replaced them with external (and cooler) diodes. But disabling the alarm doesn't make the error go away. I guess the print head will soon burn out if you try this trick.

To do this you will also have to know the pinout of the QY6-0082 print head used in the iP7260. I don't know if you can find that pinout on the web?

Here is the pinout of another print head, the QY6-0061, Notice pads #27 diode anode CL and #29 diode anode PGBK.

AFAIK QY6-0082 print heads are still available from regular dealers of Canon spare parts, but is it worth spending the money? Beware of cheap print heads from the far East. There have been many reports of them being defective out of the box.

 

[mikeg]

The print head is a large special integrated circuit. Temperature is measured by diodes on the printhead substrate, as the characteristics of a diode are temperature dependent.

This post suggests that some have "repaired" an overheating printhead by cutting the connections to the internal diodes and replaced them with external (and cooler) diodes. But disabling the alarm doesn't make the error go away. I guess the print head will soon burn out if you try this trick.

To do this you will also have to know the pinout of the QY6-0082 print head used in the iP7260. I don't know if you can find that pinout on the web?

Here is the pinout of another print head, the QY6-0061, Notice pads #27 diode anode CL and #29 diode anode PGBK.

AFAIK QY6-0082 print heads are still available from regular dealers of Canon spare parts, but is it worth spending the money? Beware of cheap print heads from the far East. There have been many reports of them being defective out of the box.

Many thanks for your words of wisdom. I was reluctant to purchase a new print head without verifying it was the source of the problem. However while searching for prices, I realised the print head in my second printer (the MG5660), was identical. It seems I have the only two Canon printers with this particular 1picolitre print-head and I was able to swap them and prove conclusively that the iP7260 head was at fault.
Considering the print-head is usable in both my printers, and heeding your advice re Chinese copies, I have ordered an original Canon part for $99. A bit extravagant I know but the image quality obtained using the iP7260 is worth the expense.
I greatly appreciate your efforts in replying to my request and I hope the experience may help someone else in the same predicament.
Cheers,
Mikeg.

 

[stratman]

Thank you for the feedback. Good to hear you are back to printing.