Whatever the problem, I have to solve it. Since it has three years of warranty, but the costs of return shipping cost almost the same as the equipment, I would have liked that Rigol had sent me a service manual, to know where to look. The oscilloscope once it stabilizes is going well, but it is the first and last time that I bought in of Rigol and tequipament. Example a year ago I bought a Chinese welding station, came with the failed display, after 45 days I received a display replacement, I changed it and now it works well.