Part 1 of 6

Chart C-1 (1 Of 6):

Display Panel Circuit:

DESCRIPTION:

The BCM supplies the FDC and ECC with certain information. Through CKT 719, the BCM sends data to the FDC. Through CKT 705, the BCM supplies the FDC and ECC with a 5 volt reference. Through CKT 751, The BCM supplies a reference ground. A clock signal is provided to the FDC and ECC over CKT 713. The BCM supplies a 16 volt source to the ECC and the FDC through CKT 716. Through CKT 718, the BCM sends data to the ECC.

NOTES ON FAULT TREE:

1. A "C" displayed on one or both panels indicates a loss of the clock signal to the affected panel.

2. A "D" displayed on either panel indicates a loss of the data signal to the affected panel.

3. If one panel is affected, only branches of the critical circuits to that panel require investigation.

4. If both panels are affected, several circuits then require investigation. If depressing the off button on the ECC does not result in the blower turning off, then the panels are not in communication with the BCM. This could be caused by a loss of 5 volts or ground to the panels. If the blower turns off, all remaining critical circuits must be checked.