Dell just release a new Thunderbolt firmware 4.26.03.001 ,A07
I installed it, and it seems to have destroyed my external HDMI port.
I tested it with different monitors and cables.
On some monitors the colors are inverted (white goes black). Some monitors don't display anything.
I hope the upgrade caused no hardware defect to the HDMI port.
Unfortunately I cannot find the old Thunderbolt firmware to got back.
Solved! Go to Solution.