There is provided an IC board and a display apparatus. Switching components (01; 02) are added between the internal interfaces (J1, J2 . . . Jn; j1, j2 . . . jn) corresponding to the backend data processing chips (U2; U3) and the frontend data processing chip (U1), or a switching component (02) is added between the internal interfaces (j1, j2 . . . jn) corresponding to the backend data processing chip (U2) and another backend data processing chip (U3). The switching components (01; 02) can ensure normal signal transmission between the backend data processing chips (U2; U3) and the frontend data processing chip (U1) or between the backend data processing chips (U2; U2) when no external test signal is input into the internal interfaces, i.e., when the IC board operates normally; and interrupt the signal transmission between the backend data processing chips (U2; U3) and the frontend data processing chip (U1) or between the backend data processing chips (U2; U3) when the internal interfaces j1, j2 . . . jn are input with an external test signal such that the impedance of the signal transmission path in the backend data processing chips (U2; U3) during the external testing remains consistent to avoid abnormal transmission of the external test signals and the signals during normal operation.