Motorola SSETM 5000 - Manual (Page 111)

6881094C12-A November 11, 2004
Troubleshooting Charts: DC Supply Failure 9-7
DC Supply Failure—Page 3
MAEPF-27393-C
Voltage
= 5.0V+/-5%?
Check Voltage
at pin 5 of
U505 (VOCON)
No No
No No
No No
No No
Yes
Yes
Yes
Yes Yes
Yes
Yes
Yes
Yes
3
Check
700-800: E6, C15,
C16, C17, and D2
VHF: E6, C6,
C8, and D2
Voltage
= V2?* Components
OK?
Check R503,
D501, C509,
C510, and C508
Replace
Problem
Component
Replace
700-800: U505
VHF: U1
Replace
Problem
Component
Components
OK?
Check Voltage
at TP7
Check Voltage
at TP6
Replace
U2
Check Voltage
at TP5
Check
700-800: D1, E5,
C12, C13, and C14
VHF: E5, C3, C4,
C5, and D1
Check Voltage
at TP3
Replace
U3
End Replace
U1
Voltage
= 5.0V+/-5%?
Replace
Problem
Component
Voltage
= V2?*
No Is unit
VHF?
Components
OK?
Replace
Problem
Component
Check
700-800: D3, R704,
C19, and C20
VHF: E7, C9, C10,
C11, and D3
Components
OK?
No No
Yes Yes
Replace
U5
Voltage
= V2?*
Replace
Problem
Component
Check
E8, C18, C19,
C20, and D4
Components
OK?
* per Standard Bias Table
* per Standard Bias Table
* per Standard Bias Table