I own three different o-scopes. My favorite daily rider is a Tektronix 2245A, circa 1990. I've had it about 20 years (purchased used) and have treated it like a little princess. Aesthetically it looks remarkably good and has maintained its measurement accuracy over the years. It has been a reliable friend indeed.
But a few days ago I powered it up and she was dead. No lights, no screen trace, only a brief hiss sound at the moment of power-on. After a 911 panic moment I collected my thoughts and mentally prepared to troubleshoot the power supply.
Here's an image of the Tektronix 2245