How to upgrade firmware 3.4.2 to 4.0.3 [2600B]

Is it possible to upgrade to v4.0.3. The info states that upgrading to 4.0.3 is only possible from v4.0.1. The latter is not available for downloading.<br> <br> So is it possible to upgrade from 3.4.2 to 4.0.1 and if so where can I download v4.0.1?<br> <br> Thank you.

2604B

The 4.x firmware of 2600B series apply only to units shipped from factory with a 4.x level.

If your 2600B has 3.x level, then 3.4.2 from Tek.com would be the most recent version.