Incorrect print cartridge error on HP 2575

SOURCE: Will not feed paper. HP Photosmart 2575

This is a very common problem. Apparently HP changed the roller because of this fault.
I've tried cleaning, I've tried making the roller rough. I tried to get HP to send me a new roller but they didn't even reply.
HP are a rubbish company who don't care at all about customers (and their printer software (bloatware) is even more rubbish).
BUT - the solution I found:
The spring that holds the roller down onto the paper is too weak. I bent the end of a straightened out paper clip into a small hook then made another hook-like bend a bit further up (but kept the rest of the clip to use like a handle). the length between the two hook parts is just under 1/2 inch. Don't cut it yet - buy you will need to when it's in place.
Hold the handle end (the bit at the bottom of this sketch) so you can fiddle about in the small space and don't loose the spring altogether.
Find the spring that fixes onto the roller gadget, it hooks onto the printer body. Hook the spring off the hole in the printer body, and then catch the second (double) hook of the paperclip onto the small printed circuit board just by the roller (most of the board is empty - so hook it to the left end of the board).
Then, when it's all in place cut the rest of the paperclip off.
You can see the double hook part once I'd cut off the "handle" piece in the photo:

and here you can see where the spring used to go, and where it fixes with the clip thingy I made.


Of course this is what I did (when I was about to throw the printer away so it was a last chance survival idea), if you loose the spring, stick it onto something that goes sparky-sparky or otherwise kill the machine or yourself I can't take responsibility!

SOURCE: INK CARTRIDGE PROBLEM Remove and check

Take the cartridge out and rub the contacts with a piece of damp tissue paper and try again.
Check the contacts in the printer itself where the cartridge sits. If there is any damage or pin hole on the white ribbon with the gold contacts on it then the printer is unrepairable but it sounds like a cartridge problem. Try changing the cartridge as well

SOURCE: Right cartridge incorrect" and "Left cartridge incorrect

Many newer HP Printers internally keep track of your cartridges by a serial number embedded into the cartridge. When it's low, the printer remembers. This is entirely done within the printer itself, and not the printer software. Some printers EXPIRE the cartridges after 18 months according to the installation date even it is not empty.

Outrageous, but true.

A fix? Most HP printers will only keep 2 cartridges in memory, so if you have 2 extra cartridges, (even empty ones) you could cycle them through to reset the printers memory, and reset the ink level to full. Basically, even though you've refilled your cartridge, the printers has the cartridge's serial number stored in memory. This will reset it.

SOURCE: my hp photosmart 2575 says

open the front cover the cartriges will come in the centre position where you can remove the cartridges check which cartridge is on your right side remove and clean the brown dotted circuit on both the printer and cartridge with the tissue paper .insert it back in the proper position and then check if the same problem then remove and replace the cartride printer will work properly.thanks

SOURCE: Printer reads "Incorrect Print Cardtridge Installed"

According to the HP website, the correct cartridge for the HP PSC950 is HP15 or HP78. Comes in black only or tri-color.