A print head control circuit configured to control an operation of a print head having a function of performing self-diagnosis in accordance with signals (DIG1, DIG2, DIG3, DIG4, DIG5) input from a first coupling point, a second coupling point, a third coupling point, a fourth coupling point, and a fifth coupling point, the print head control circuit comprising: a first cable including a first drive signal wiring group, a second drive signal wiring group, and a first diagnostic signal wiring group; a second cable including a third drive signal wiring group, a fourth drive signal wiring group, and a second diagnostic signal wiring group; a diagnostic signal output circuit configured to output a first diagnostic signal, a second diagnostic signal, a third diagnostic signal, and a fourth diagnostic signal; and a drive signal output circuit configured to output a first drive signal and a second drive signal that cause the print head to discharge liquid, wherein the first diagnostic signal wiring group includes first diagnostic signal propagation wiring (197a-21) configured to propagate the first diagnostic signal input to the first coupling point, second diagnostic signal propagation wiring (197a-17) configured to propagate the second diagnostic signal input to the second coupling point, and third diagnostic signal propagation wiring (197a-14) configured to propagate the third diagnostic signal input to the third coupling point, the second diagnostic signal wiring group includes fourth diagnostic signal propagation wiring (197b-10) configured to propagate the fourth diagnostic signal input to the fourth coupling point, and fifth diagnostic signal propagation wiring (197b-16) configured to propagate a fifth diagnostic signal input to the fifth coupling point, the first drive signal wiring group is configured to propagate at least one of the first drive signal and the second drive signal, the second drive signal wiring group is configured to propagate at least one of the first drive signal and the second drive signal, the third drive signal wiring group is configured to propagate at least one of the first drive signal and the second drive signal, the fourth drive signal wiring group is configured to propagate at least one of the first drive signal and the second drive signal, in the first cable, the first diagnostic signal wiring group is provided between the first drive signal wiring group and the second drive signal wiring group, in the second cable, the second diagnostic signal wiring group is provided between the third drive signal wiring group and the fourth drive signal wiring group; and the first diagnostic signal propagation wiring also serves as wiring that is configured to propagate a signal defining a discharge timing a first cable including a first drive signal wiring group, a second drive signal wiring group, and a first diagnostic signal wiring group; a second cable including a third drive signal wiring group, a fourth drive signal wiring group, and a second diagnostic signal wiring group; a diagnostic signal output circuit configured to output a first diagnostic signal, a second diagnostic signal, a third diagnostic signal, and a fourth diagnostic signal; and a drive signal output circuit configured to output a first drive signal and a second drive signal that cause the print head to discharge liquid, wherein the first diagnostic signal wiring group includes first diagnostic signal propagation wiring (197a-21) configured to propagate the first diagnostic signal input to the first coupling point, second diagnostic signal propagation wiring (197a-17) configured to propagate the second diagnostic signal input to the second coupling point, and third diagnostic signal propagation wiring (197a-14) configured to propagate the third diagnostic signal input to the third coupling point, the second diagnostic signal wiring group includes fourth diagnostic signal propagation wiring (197b-10) configured to propagate the fourth diagnostic signal input to the fourth coupling point, and fifth diagnostic signal propagation wiring (197b-16) configured to propagate a fifth diagnostic signal input to the fifth coupling point, the first drive signal wiring group is configured to propagate at least one of the first drive signal and the second drive signal, the second drive signal wiring group is configured to propagate at least one of the first drive signal and the second drive signal, the third drive signal wiring group is configured to propagate at least one of the first drive signal and the second drive signal, the fourth drive signal wiring group is configured to propagate at least one of the first drive signal and the second drive signal, in the first cable, the first diagnostic signal wiring group is provided between the first drive signal wiring group and the second drive signal wiring group, in the second cable, the second diagnostic signal wiring group is provided between the third drive signal wiring group and the fourth drive signal wiring group; and the first diagnostic signal propagation wiring also serves as wiring that is configured to propagate a signal defining a discharge timing