The error code 1686 means black ink level gone, press and hold the "stop" button for 10 seconds, so does with color side.
Usually, the printers with cartridge number 61/60 can work on single cartridge mode, e.g. deskjet 3050A all in one machine.
America is a country where half the money is spent buying food, and the other half is spent trying to lose weight
by using some compatible hp 950/951 cartridges, the printer will pop up ink system error massage and stop there; what we've done was just refill the original ones and install them, problem solved.
by pressing and hold 2 buttons on D7260, we fixed the error 18a0001
(Bottom Left) (Top Left) (Bottom Left) (Bottom Left)
1) Enter Service mode by pressing: menu-copy-#
2) select: Test Mode
3) select  printer test in test mode
4) select 3 [eeprom clear]
5) select 0 [ink count]
6) press the [stop/reset] key (returning to the state of 3), and press the [on/off] key