AMX error 45c

error 45C
1. Check For 80 VAC At CR4 Black Leads On AMX1A4 Panel With
PREP Pressed
2. Check For About 75 VDC Across AMX1A4 C2/C12 With PREP
Pressed
3. Check For Correct Polarity Of CR1 & CR2 (CR7/CR13)
On AMX1A4 Panel
4. Bad 1KHZ Board
5. Are The Tap Relays Energizing?
6. Is “Stop Cap” At J4-11 (1 Khz Board)
Approximately 80 VDC?
ERROR