Dug into the manual for the 2445, and found...
...a warm-up period of at least 20 minutes, and is operating at an ambient temperature between -15°C and +55°C. (unless otherwise noted).
Ok but the Tek 2445 is valvular, it's like the old TV or radio equipment, it is incredible that this happens with a digital equipment. My doubt is that if it is a poorly welded component this will worsen or directly die. And another thing the people of Tequipament and Rigol leaves much to be desired, since they were dedicated to dodge the problem before recommending any advice to review the equipment.
The only valve in a 2445B is the CRT (or any other 24xx or 22xx series). Everything else is purely solid state.
If I understand the rest of your statement/concern, are you talking about thermal cycling of a bad solder joint?
- If this turns out to be the case, at least it's an easy fix.
As per your issues between TEquipment and Rigol, it's ultimately the compromise made by purchasing it in US at an acceptable price (not even sure there is an Argentinian distributor
). The global locations make it a mess.
Technically this is a
grey market purchase. FWIW, some manufacturers even use this as an excuse to void the warranty unless it's sent back to the original country of purchase.
For clarification (further information on link)...
What is the 'Grey Market' The grey market, also referred to as the parallel market, is a market where a product is bought and sold outside of the manufacturer's authorized trading channels.
Of course, this is getting outside of what's going on with your scope.