Powering on my Hughes & Kettner GrandMeister Deluxe 40 guitar amplifier after changing the tubes

Tonight on April 16th 2023 I changed the power tubes in my Hughes & Kettner GrandMeister Deluxe 40 guitar amplifier because the O.E.M. Shuguang EL84 power tubes were wearing out as the filament was deteriorating normally over the span of nearly 3 years since I bought this amplifier new from Sweetwater in July of 2020.
I bought a matched set of four Genalex Gold Lion EL84 power tubes that I carefully installed myself while using paper towel to prevent touching the tubes so I wouldn't get any of the oils from my hands onto the glass of the tubes.

[@PeterMoore350]

Oh you did it in standby mode too.
No.
Power it on, wait for that click sound.
Take it out of standby mode then put it in full 40W mode before you do the guitar pick test.
Give it some time to warm up too before you do it as it’s pointless doing it on the amp when you’ve only powered it in for 5 seconds and room temperature is like 5 C
Cheers from NZ 😎🎸🤘

[@PeterMoore350]

5:59 You’re supposed to do the guitar pick test in full 40W mode not t in 1W mode.

[@krystufektrvaj1692]

what exactly this flashes means?