Is it possible to recover the block programming database from a failed GCM-84000 series controller?

Issue

Is it possible to recover the block programming database from a failed GCM-84000 series controller?

Product Line

TAC I/A Series

Environment

Network 8000 GCM-84000 series controller

(1) failed CPU board, GCMA-112

(1) replacement CPU board, GCMA-112

Cause

A GCM-84000 series CPU board has failed, and a backup of the GCM block database cannot be found to install in a replacement controller.

Resolution

It MIGHT be possible to extract the block database from a failed GCM-84000 series controller, as long as the PROM chips on the CPU board (GCMA-112) were not damaged by the "event" that damaged the rest of the CPU board.

Assuming the PROM chips are not damaged, the procedure is as follows:

Note: When changing the PROM chips, be sure to wear a well-grounded ground strap to help prevent static electricity from damaging the sensitive chips.

1. Remove the chips labeled PROM-22-300 and PROM-22-400 from the "old" CPU board.

 

 

2. Install them on the spare CPU board. Do not interchange the PROM chips, and maintain their original orientation.

3. Replace  the CPU card into a working GCM. If the original PROM chips were undamaged, the GCM will reboot successfully, and the block database from the original GCM will now be transferred to the replacement GCM. 

4. Backup the GCM database immediately.