How do I initiate a calibration for my HP Photosmart C4780? for some reason, when I replaced my ink cartridges, the printer never did a calibration.

You can gain access to the service menu...refer to Cartridge Error Clear bypass procedure below (as guidance of how to get in):

For any severe cartridge error related message, on the HP C4600, C4700 or D110a printer models, I suggest you run the internal Tap 41 diagnostics test which will tell you the electrical health of the ink cartridge - in many cases the cartridge is internally electrically damaged and will need to be replaced. In addition, you can temporarily bypass an 'incompatible cartridge(s) or Missing/Not Detected error message by performing the Cartridge Error Bypass procedure...refer to two Youtube videos on how to do this:

HP Photosmart C4600 & C4700 Printers - Tap 41 Diagnostic Test: http://www.youtube.com/watch?v=ghxjLCn07Jo

HP Photosmart C4600 C4700 D110a Printers - HP 60 Cartridge Error Bypass: http://www.youtube.com/watch?v=rNVJmKPlLsg

Low Ink Warning and Other (i.e Incompatible Cartridge) Errors, HP 60 & HP 61 Ink Cartridges:

http://www.youtube.com/watch?v=5_suW3U6e08

Hello,

Please check the ink level in the cartridges before you start to make a copy. You may have to replace the cartridges which are depleted or have low level ink.

If cartridges have ink in them and if the printer is not making a COPY ( black or color ), then have the printer power cord directly plugged in to wall outlet ( bypass the surge / power strip ) and retry making a COPY.

If issue still persists, then you may have to call HP Tech Support for further assistance as the printer would require a service.

Hello,

While the printer is ON, remove the cartridges and you may unplug the power cord from back of the printer.

Wait for 30 seconds.
Ensure the cartridges have ink in them ( atleast 25% ).
Plug in the power cord to the back of the printer. If printer does not power up, press the Power button on the printer to do so.

Initialization should complete.
If issue still persists, please call HP Tech Support for further assistance as the printer may require a service.

Yes it could be the problem. Try and get a different print cartridge and if it doesn't work you may just have to get a new printer.

Calibrate the printer.

You may have a dud. Try using the cartridge in another printer of the same model. Otherwise return it to the store and have them test it or exchange it for another one.

Ok. As per your statement , the power cable is working properly. So , the problem is with your printer only. If you are using the original cartridges and still having the priblem , it is only the defualt printer. If you are having the extended warnty for (3) years , you are adviced to contact ' HP Authorised Service Partner'. they will replace your old printer with new one. Generally the HP company is giving 1 OR 2 years warranty for replacement.If have paid extra amount for extended warranty , your printer may have warranty up to (3) years. So, within the period of (3), the HP Authorised Service Center will replace your printer. They will give reciept for your old printer, and replace your prionter within a (15) days to (25) days with new one. If the printer is not having warranty or extended warranty , the printer is assumed to be as damaged. So, you have to purchage the new one. Be, cuacious the HP printers are not repairable. Please don't try to approach the local repairer.They will eat your money and also don't try to purchase very very very costly HP in cartridges. I think your problem may be solved.

These types of severe cartridge errors (i.e. "refer to documentation" / "incompatible cartridges", etc.) typically indicate the internal micro-electronics of the HP #60-61 cartridge are electrically damaged. The cartridge's electrical wire runs at rear and lower side of the ink cartridge, are very delicate and are somewhat susceptible to ink attack over time, which can lead to premature failures. In addition, the older the cartridge the higher the chance of an internal electrical failure due to prolonged ink exposure and subsequent circuit corrosion. I suggest you always run a 'Tap 41' diagnostic test to check cartridges electrical health (this is a forced test); you may also bypass the error (temporarily) on C4600-C4700 models which use HP 60 cartridges. Refer to Inkjet411 youtube videos below:

HP 60, 60XL, 61, 61XL Ink Cartridge Refills - Solving Errors & Warnings: http://www.youtube.com/watch?v=BskAfa6NJSg

HP Photosmart C4600 & C4700 Printers - Diagnostics Tap 41 Test: http://www.youtube.com/watch?v=ghxjLCn07Jo

HP Photosmart C4600 C4700 D110a Printers - HP 60 Cartridge Error Bypass: http://www.youtube.com/watch?v=rNVJmKPlLsg

HP Deskjet F2400 F4400 and F4500 Printers - Diagnostics Tap 41 Test:

http://www.youtube.com/watch?v=m-OM09NvNqg

HP Deskjet 4200 Printers - Diagnostics Tap 41 Test:

http://www.youtube.com/watch?v=16uXSBwTan8

HP Deskjet D2500 & D2600 Printer -Tap 10 Diagnostic Test:
http://www.youtube.com/watch?v=RTFOBtdthAc

Switch off the printer and switch on again,Unclip the cartridges one by one and clip back in again this sometimes cleans out the connector pins.This has happened to me.

Filling your cartridge with non-HP ink won't cause an error. There are basically two reasons for ink system failure, The cartridge is no good or the ink system has failed. Some of these machines can be reset. But, try replacing cartridge first.