Change resolution in pi 2

Hello, I’m trying to change the resolution on my pi 2 and having problems, it’s connected to a HDTV which is pretty old and crappy and defaulted to 1280x1024 which I can’t change, I believe native resolution is 1366x768 but I know for a fact 720p 60hz works fine, which is what I’m trying to change to. I’ve added a new mode with xrandr but when I try to change to it it gives error xrandr: configure crtc 0 failed. I’ve disabled overscan in /boot/config.txt is there anything I can do? Thanks.

Hi @Dave_Young,

try the following (I haven’t read it btw!):