I refill the yellow toner, but printer says replace the yellow one

SOURCE: printer toner refilling

you can fill it by yourself.
1. buy good qulity magnatic toner powder.
2. basic for oppening 12a toner is 2 SIDE SMALL PIN, YOU CAN EITHER PUT THESE PINS INSIDE THE TONER WITH THE HELP OF HAMMER AND NAIL.OR OTHER TRICK IS TO FIRST OPEN THE GEAR SIDE TWO screw BY PHILIPS SCREW DRIVER and pick up drum then with the help of l type sharp longe nail try to pull pins from inside to out side this by process you see you get two part of toner cartridge one is wast chamber another is main chamber smaller one is wast cleane it .

open the both side of main chamber by unscrewing 4 screw ond pour the toner power powder in that main hopper and do all the steps in vice versa. your toner is filled TAKE A TEST PAGE.

I can frovide you photos step by step mail me [email protected] if neded

SOURCE: yellow toner not being recognized with new toner installed

Probably dirty contacts on side of cart. Also if you take out drum and cart unit together, clean copper contacts with alcohol and cotton bud, also make sure in machine where they contact is clean