Unofficial hardware upgrades

From Juniper Clue

This page contains undocumented or unsupported information. Use caution and common sense, as the information herein may pose a greater risk of triggering bugs, voiding warranties, or damaging equipment than other material on this site. See our disclaimer for more information.

M20 SSB

A 64MB IP2 SSB on an M20 can be upgraded to 128MB by adding a second 64MB DIMM. You can grab one from an unused SSB or buy one pretty cheaply. The specifications are:

• 64MB (8Mx72)
• 3.3v 168 pin
• EDO
• Unbuffered
• ECC
• 60ns, 4K refresh
• 9 chips

DIMMs taller than 1.25 inches probably won't fit.

Source for cheap compatible DIMMs Tested and works.

M5/M10 FEB

Factory original SDRAM on M5/M10 FEB

DIMMs that are too tall won't work

A M5 or M10 FEB can be upgraded from 64MB to 128MB of SDRAM. There is only one DIMM socket on the board, so you must replace the DIMM entirely. The specifications are:

• 128MB 144-pin SODIMM
• PC100 CL2
• ECC
• Must be 9 chips
• Must be very low profile

The memory module is electrically compatible with a Cisco compatible part MEM-NPE-400-128MB or MEM-MSFC2-128MB. However, the MEM-NPE-400-128MB is physically too large to fit. A third party version of the MEM-MSFC2-128MB works fine and fits correctly.

Source for cheap MEM-MSFC2-128MB compatible modules Tested and seem to work in M5/M10

It is possible to use larger modules than 128MB, for example 512MB. Tested to work is a module from SMART, partno SM572648578D9BPID0 with 512MB. However only 128MB will be recognized by JunOS.

M7i/M10i cFEB

A M7i/M10i cFEB can be upgraded from 128MB to 256MB of SDRAM. There is only one SO-DIMM socket on the board, so you must replace the DIMM entirely. The specifications are:

• 256MB 144-pin SODIMM
• PC133
• ECC
• Must be very low profile

The memory module is compatible with a Cisco compatible part MEM-MSFC2-256MB. A third party version of the MEM-MSFC2-256MB works fine and fits correctly.

Juniper uses memory from SMART (Partno SM5JPN32M72001) in the original MEM-FEB-256-S upgrade kit for M7i/M10i.

Memory Testing

 !!! BEWARE !!!

1. The SO-DIMM module shown above is the CPU SDRAM of the PPC. The diag below tests the soldered SDRAM near the B-CHIP and SRAM.

2. The FPC and PICs _MUST_ be OFFLINE or UNCONFIGURED in the Juniper (CLI), or you WILL get random failures in this test that do NOT indicate a problem.

You can test FPC DRAM (not SSB DRAM) from the SSB's diagnostic interface. For example, using the following commands, you can test FPC 0's DRAM:

* start shell user root
* vty ssb/feb
* bringup chassis slot-state 0 diag
* diagnostic set mode manufacturing
* diag clear log
* diag bchip 0 sdram 

SBR(router vty)# diag bchip 0 sdram

[Waiting for completion, a:abort, p:pause]

B SDRAM (Slot 0) test

phase 1, B SDRAM (Slot 0) test: Address Test

phase 2, B SDRAM (Slot 0) test: Pattern Test

phase 3, B SDRAM (Slot 0) test: Walking 0 Test

phase 4, B SDRAM (Slot 0) test: Walking 1 Test

phase 5, B SDRAM (Slot 0) test: Mem Clear Test

B SDRAM (Slot 0) test completed, 1 pass,  0 errors

Afterwards disable diag mode:

* diagnostic set mode bring-up
* bringup chassis slot-state 0 on-line