I've been using turbo print for some time, and I have found some interesting issues and solutions regarding the Canon i9900 photo printer. Cleaning the print head is generally a bad idea, because then it's just living on borrowed time. You can replace the print head up to 2 or 3 times within the first five years. After that the purge unit must be replaced along with the print head. Since the i9900 is the most recent decent consumer/professional printer Canon ever made, simply because the ink cartridges are not mined with microchips, it's usually worth it to repair them.
I have learned that you must follow the instruction given by the driver dialog boxes. Most people fail to observe the instruction that: bad output should be addressed first with a regular nozzle clean. If you jump right to the 'deep clean,' the printer was not designed for that. It was designed to perform a deep clean after 1, 2 or 3 regular clean + nozzle check printouts. Then you can move to deep clean + nozzle check.
The second mistake is to clean the heads but then skip the print nozzle check pattern, and jump right from print head clean to production image printing. After a print head clean, you must print a nozzle check pattern. After nozzle cleaning, if you don't print the nozzle check pattern before you begin production print jobs, the jobs frequently fail. If you print the nozzle check pattern, and it looks right, the printer continues to print properly until it is left idle for several weeks.
You cannot prime a new print head with non-OEM ink, or the print head will burn out, unless you use the secret method. In the USA we can purchase hypodermic needles and syringes at any drug store (pharmacy) without a doctors order. You need to state a legitimate purpose for the intended use of such items, i.e. something other than intravenous injection.
When I'm priming a new print head, I open bottom ports of the set of non-OEM ink, set them upside down on a piece of plastic (no mess), and carefully inject between 1-1.5 cc's 90% isopropyl alcohol into each cartridge. Canon's secret is alcohol-based ink. Alcohol-based is less viscous than water-based, so when the cartridge is completely dry, i.e. new, you have to put alcohol-based ink in before you use water-based, non-OEM cartridges.
The injected alcohol is enough to successfully complete printer's priming routine without ruining the new print head. The aforementioned reason is why replacing the print head many times fails to alleviate print problems, and, of course, turboprint gets the blame. After the first five years the purge unit should be replaced..
For logic board errors, power off printer. Download the latest firmware and installation utility (one file I think) from Canon.com. Use the USB 1.1 connect on the i9900. Before you power up the printer, lift the big chrome-plated bar inside the front cover and slide the print head to the middle. Leave the front cover open. Power up the printer and you will no longer get the error.
Flash the firmware into the printer using the Canon firmware packaged with the firmware upgrade download. You'll need the service manual for this next one: to complete the repair, put the printer in service mode, reset the eeprom, and power down. Move the print carriage as earlier and leave the front cover open. Power on the printer and wait a few minutes. The carriage should move a little. Close the cover and the carriage should move into locked position (to the right).
The logic board error should be gone.
Print is magenta cast. Power on the printer. Pull the power cord out of he wall socket. Remove the USB cable from the printer. Wait 30 seconds Plug the power cord in. Attach the USB cable. The other end should be attached to a powered up PC. Power on the printer. The magenta cast should be gone.