lost connectivity between two 3300 after upgrade

[lyzard00]

hi

i have two 3300 mxe in rls 4.1 connected each other for ipx/net.

one is label as main and second is label as gateway.
it working fine about 4 yrs. i need upgrading because phone 5330e is not supported in rls 4.1
i did the upgrade to the main and they working perfect ,one week later i did the upgrade to the gateway, here is my problem,
when the equipment is up and running, after 30 minutes I lose communication with the main.
I have to go through the serial port on the gateway and type this command: mips_reset
retrieves the connectivity for 30 minutes more.

[lundah]

Bad controller chassis, specifically the MIPS processor which runs the internal L2 switch. Known issue, only fix is to replace the controller chassis.

[lyzard00]

I replace the chasis but still the same

[lyzard00]

Can i use the 4.1 backup on rls 6.0?

[marcolive]

Yes, there is an upgrade path from 4.1 to 6
Try this command in maintenance command : upgrade bootrom all
This wil upgrade MIPS firmware
Hope that helps!