UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE

Perform the procedure in Figure 4-33to confirm the cause of the DC-48V fuse blown fault.

Start

Visual check: No pin contacting or backboard melting?

OPE Lamps (green) of

No

LC/TRK/NCU cards remain lit?

 

Yes

 

1. Turn ON (UP) the MB key on the circuit card.

2. Remove the card from the PIM.

3. Replace the fuse with a new one.

The replaced fuse is blown again?

Yes

LPM / TSWM / PIM

Make sure in which module the fuse has blown

No

Fault of circuit card that was removed

Insert the removed cards

No

one by one (into the PIM). Is any fuse blown?

Yes

Fault of circuit card that accompanied the fuse blown.

Turn ON (UP) the MB keys on the whole circuit cards, and remove them from the PIM. (Only PWR cards are inside the PIM)

Replace the blown fuse with a new one.

No

The replaced fuse

 

 

is blown again?

 

 

Yes

 

 

Replace the PWR card

 

 

The fuse is still blown?

No

 

 

 

Yes

 

Turn ON (UP) the MB keys on the whole circuit cards, and remove them from the PIM. (Only PWR cards are inside the PIM)

Replace the blown fuse with a new one.

Insert the removed cards one by one (into the PIM). Is there any fuse blowing?

Yes

Fault of circuit card that accompanied the fuse blown.

No

Perform system initialization after inserting all removed cards.

Fault of PWR card.

Perform system initialization after inserting all removed cards.

There is a short circuit on the backboard of the PIM.

Figure 4-33 DC -48V Fuse Blown Fault Flowchart

CHAPTER 4

NDA-24300

Page 308

Issue 1

Page 335
Image 335
NEC NDA-24300 manual DC -48V Fuse Blown Fault Flowchart