4. Disconnect the power cable/cables from the main circuit board.
a
CAUTION: Always disconnect the power cable first to prevent current spikes that may harm
the circuit boards or the battery.
5. Disconnect the HMI cable from the main circuit board.
6. Remove the upper chassis.
430X, 430XH, 450X, 450XH, 520, 520H, 550, 550H
7