Hi! I would say if it’s just a single pickup shaft spin during certain period of time - and you having problem with second paper being picked up - that could be separation pad that is worn (and should be replaced), but if that shaft spinning twice during one pickup cycle and that is causing double pickup - that’s issue with solenoid (foam pad it’s not good in there and could be replaced with 2 cut pieces of any duct tape). Good luck!
Most likely - It could be loud sound of toner cartridge, another version for that - fuser film needs to be oiled or replace due to insufficient amount of oil under it and worn out. Next thing I would check - is feed roller. But I'm assuming - it's cartridge. If you have another one - try to put it in and check how it sounds to your ears.
Hello! To start with obvious. Missing color - check ink cartridge itself, then inspect tubes that involved into move inks from cartridge to print head. If you have no leaks and inks are there (no bubbles or air in tubes) - then you very likely need to replace printhead for your printer. As I guessing - it should be 1 printhead for 4 colors. That is how your nozzle test should look like If you decide to go with new printhead - you can find them online. Just type PRINTHEAD and model of your printer. Replacing procedure itself - is messy but you can do that. Don't forget to grab pack of gloves in nearest local shop. And - for that procedure there are some videos on Youtube, and should be service manual (with step by step instruction). Bear in mind - that very likely you would need new ink cartridges - as after installation of printhead you would be performing "cleaning" tool one by another - just to get inks from cartridges to new printhead. Good luck! "May the Force be with you!"
Here is what you can do. That helped me once. You need to get to mainboard and find there flash memory. In my case it was chip - 25Q64BVFIG. It contains firmware for that machine. Then - need to desolder it, reprogram using programmer with support of that type of schemes and solder it to mainboard again. Downbelow will be a link for dump to download (must mind you - that Canon iR-2420 was in Russia and I'm not sure about differences between US/Canada and European firmwares. Just to let you know that beforehand - that there might be some problems to show up. But I suppose - since machine will finish loading inner software and comes to ready state - you can just figure it out by playing with local/country settings). These are photos before and after (connector melts a little) - About dump - it's ready to use with your programmer - it's been taken from newly installed machine (not by me - but from guys from similar Russian tech forum). DUMP for reflash memory chip - About programmer - mine is - TL866A -...
It's common problem for these adf units. Here is link. It's translated with google. It might works for you. In general - you will need to resolder (or reconnect any other proper way) cables coming from adf board to adf itself. https://translate.google.com/translate?h...-kazan.ru%2F%3Fp%3D11_18&sandbox=1 Good luck!
If upgrading firmware - is acceptable procedure for this type for machine and can be done by regular user - then you probably can be covered by vendor warranty and need to call to official HP service company nearest to you.
There are 2 error codes - up here. First one - basic, and second code - for fatal errors to detect exact problem. Here is link. It's translated to English page that can be useful for you. https://translate.google.com/translate?h...