i2cdetect fails

I have a Raspberry Pi 2 model B, running Volumio 1.55. I am preparing to add an I2C device and I would like to use I2CDETECT to verify the I2C bus wiring. I have done the following:

a) in file etc/modules, add the two lines:

i2c-bcm2708 i2c-dev

b) looked for file /etc/modprobe.d/raspi-blacklist.conf - does NOT exist, so no need to edit

c) in file /boot/config.txt, add the two lines:

dtparam=i2c1=on dtparam=i2c_arm=on

d) Install i2c-tools

e) reboot

When I try this:
sudo i2cdetect -y 1
I get the error message:

Who else has this setup working? and how did you do it?

Thanks,
Jake

I took a fresh copy of the Volumio 1.55 image and tried the above steps - and it worked fine. So, I must have messed something up along the way.

Jake