UNIT/CIRCUIT CARD REPLACEMENT PROCEDURE

Perform the procedure in Figure 4-32to confirm the cause of the RGU fuse blown fault.

Start

 

 

 

Visual check: No pin contacting

 

 

 

or backboard

 

melting?

 

 

 

 

 

 

 

 

 

 

 

 

 

 

OPE Lamp (green) of

No

 

 

each LC card

 

remains lit?

 

 

 

 

 

 

Yes

1.

Turn ON

(UP) the MB key

 

 

 

 

 

 

 

 

 

on the LC

card.

No Replace the blown

 

fuse with a new

2.

Remove

the card from the PIM.

one. The fuse is blown again?

3.

Replace

the fuse with a new one.

 

 

Yes

 

 

 

No

Perform station-to-station connections within the PIM. Is any fuse blown?

Yes

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

The replaced fuse

No

 

 

 

is blown again?

 

 

 

 

 

 

 

Yes

Perform station-to-station

 

 

 

 

 

No

 

 

connections within the

PIM.

Turn ON (UP) the MB

 

 

 

Is any fuse blown?

 

 

 

keys on the whole LC cards,

 

 

 

 

 

 

Fault of LC card that accompanied the fuse blowing.

Replace the blown fuse with a new one.

and remove them from the

Yes

Fault of LC card

PIM. (Only PWR cards are

 

that was removed

inside the PIM)

 

 

 

 

 

 

 

Fault in LC card that accompanied

Probable Cause: Not confirmed.

No

The replaced fuse is

Needs further observation of the fault

 

blown again?

 

 

 

 

 

Yes

the fuse blowing.

Replace the blown fuse

with a new one.

 

 

 

 

 

 

No

The replaced fuse

 

 

 

 

 

 

 

 

is

blown again?

 

No

Insert the removed cards

 

 

 

Yes

 

one by one (into the PIM).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Is any fuse blown?

 

Replace the

PWR card

 

 

 

 

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

No

 

 

 

 

 

 

 

Fuse is still blown?

 

 

Fault in LC card that accompanied

 

 

 

 

 

the fuse blowing.

 

 

 

Yes

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Perform system initialization after inserting all removed cards.

Fault of PWR card.

There is a short circuit

on the backboard of the PIM.

Figure 4-32 RGU Fuse Blown Fault Flowchart

NDA-24300CHAPTER 4

Page 307

Issue 1

Page 334
Image 334
NEC NDA-24300 manual RGU Fuse Blown Fault Flowchart