Hi, my 3405B is stuck in AC coupling on all four channels. I will be sending it back for repair but I wanted to understand what part of the circuitry was fried and what caused the failure. At the time of the failure I was looking at a 28 VDC power supply and think that it might have been a related to how the scope/laptop was grounded versus the power supply. Anybody have any ideas?
Thanks in advance, Bill