Assembly-Level Service
Theory of Operation
2-15
Table 3-6. Power Supply Block Interconnections
The following signal name information in table 3-6 on page 3-23 is
changed:
• The voltage range in the third row is changed from 22-42 Volts to
40-58 Volts.
• The voltage range in the fourth row is changed from 32-38 Volts to
45-51 Volts.
• The voltage range in the fifth and sixth row is changed f r om 22- 42
Volts to 40-58 Volts.
• The only signal names present in the tenth row are: DC Valid, DC
Valid Return, AC Valid , and AC Valid Ret ur n.
A1 Motherboard Circuit Description
Overvoltage Protection Circuit
The dc voltage ratings specified in the last sentences of paragraphs four
and five on page 3-24 are changed:
56 Vdc is 72 Vdc and 50 Vdc is 65 Vdc.
The dc voltage rating specified in the last sentence of paragraph three on
page 3-25 is changed:
56 Vdc is 72 Vdc.
External Dc Input Circuit
The paragraph that describes the external dc input circuit on page 3-25
is changed:
A1J1 receives the dc input from an external dc source (40- 58V) . The
dc voltage is then routed to a filter consisting of A1L1 and A1C2
before being sent t o A11 Power Steering Logic Assembly via connector
A1J4. Diode A1CR2 prevents any damage to the inst rument if the
external dc-input source is reversed. The current handling capability
of A1CR2 is higher than that of the external input fuse (2.5A) so the
fuse blows before the diode fails.
Option 048:
Option 048:
Option 048:
Option 048: