iP3600 nozzle check not clearly showing electronic failure

[PeterBJ]

Update3:

The print head is now ruined and possibly the logic board is ruined too. The printer flashes 10 times yellow and green in a cyclic pattern and gives the Error code B200. According to the service manual this means that the print head voltage is abnormal i.e. the print head is defective. The suggested repair is to replace both print head and logic board.

I knew the risk involved but had decided to go ahead with more aggressive cleaning methods until I had either a success or a failure.

What killed the print head was a 15 minute bathing of the ceramic nozzle plate in a 80C/176F strong solution of dish washer powder in demineralised water. After the bathing I rinsed the print head with demineralised water and after that denatured alcohol to absorb water residues. I also let the print head dry for an hour after the alcohol rinse, but the print head seems to have developed a short circuit.

So the advice not to pressurize or dismantle print heads is still a good one in my opinion. Well, at least the experiment confirmed what I already knew.

Don't do this if the printer is a valuable one!

 

[turbguy]

What's the ingredients of "Dishwash Powder"?

Hopefully you don't mean automatic dishwasher detergent...that can be corrosive to certain materials...

Wayne

 

[PeterBJ]

It was exactly that I used, detergent for automatic dish washer machines in form of a powder, that I dissolved in demineralized water. The active ingredients in many such powders are Sodium Carbonate and Sodium Carbonate Peroxide. Many Sodium salts are hygroscopic, and a moist deposit of salts is conductive.

Corrosion products or just residues from the cleaning solution, that I hadn't removed even if I rinsed the nozzle plate thoroughly, caused a leakage current that killed the print head, I think. This whitish stuff located between the terminals of the head EEPROM (?) is what I think caused the print head failure. I think this place on the backside of the circuit board is the worst place to get water or cleaner residues. Note the white deposits between the terminals of the IC. Here is a scan of the IC. The brown spot above the IC is not burnt but a shadow from scanner lamp.

Ammonia solution is a much better alkali for print head cleaners. It decomposes into ammonia gas and water, leaving no conductive residues.

 

[The Hat]

If you decide to do a full wash cycle on you print head again, you should finish off by spraying the electrical contacts
with a good dose of WD 40 and rub that in with a brush then wash that off with alcohol and you wont get continued corrosion..

 

[PeterBJ]

Sadly it is too late now, but an examination of IC and surrounding area with a magnifier and a good light source and the WD-40 treatment might have saved the print head. I won't do more experiments with detergent for dish washing machines. I will only use the European equivalent of Windex, the Ajax window cleaner or pharmacist's cleaning solution in the future.

 

[ThrillaMozilla]

Can you suck fluid through instead of forcing it? This would automatically limit the pressure difference, and might be safer.