Experiencing the following alarm event log on your Juniper EX switch?
Alarm time Class Description
2016-01-20 07:12:04 UTC Major Upgrade bank is empty or corrupted for FPC 0, please do standard upgrade sequence
This is likely because your switch was running an inferior JunOS version than 10.4r3 and it was upgraded to a greater version, which require the new jLoader.
(This is actually documented by Juniper on the technical support note referenced as TSB15524)
IMPORTANT : I would suggest looking at your running software version to ensure this is your case, I never tried running an inferior JunOS version than the one intended to be supported by this newer jLoader – I would expect your switch to fail at boot!)
To upgrade jLoader, follow the following steps :
1. Download jLoader 12.1r3 from Juniper (make sure you select the right one for your platform, failing to do so will brick your switch!) As example, here is the link for either EX3200 or EX4200
2. Upload/download the package to a temporary location on the switch filesystem (such as /var/tmp) or load it on a MSDOSfs formatted USB memory (and connect on the switch).
3. Upgrade jLoader (example) :
request system software add validate /var/tmp/jloader-ex-3242-11.3I20110326_0802_hmerge-signed.tgz
4. Reboot the switch upon successful output :
request system restart
Your switch should now boot on the new jLoader.