From upstream ticket 2392:

We had a report of sensors-detect breaking the display of a Lenovo g50-80
laptop:

 http://lists.lm-sensors.org/pipermail/lm-sensors/2015-May/043905.html

There is an I2C chip at address 0x4f on the DPDDC-A bus which reacts weirdly to
SMBus Read Byte transactions. Most likely it interprets them as writes,
treating the register address as a value.

Fixed by:
sensors-detect: Detect graphics card in all cases
http://www.lm-sensors.org/changeset/6282

and:
sensors-detect: Skip addresses 0x37 and 0x4f on DDC channels
http://www.lm-sensors.org/changeset/6283

This is somewhat similar to bug #838619, but requires an additional fix.