Are you 100% positive you put the fuse in the correct position?
There's kind of a little storage box built into the fuse holder for a spare fuse, then a little clip below it that is where the fuse should go.
Beyond that, you can set your meter to AC volts, and measure the AC voltage between L and N on the IEC entry module to be sure you're getting power into the amp.
You can then flip the switch on and measure the AC voltage on the 0-120 terminals on the PT-3 power transformer to check that the AC voltage is making it to the power transformer.
-PB