While attempting to diagnose an intemittant backlight problem, I noticed that when I opened my C860 VERY slowly the screen would initially come on in portrait mode & then switch to landscape after the top was raised by a certain amount.
Look on the face of the hinge. The C860 has "SHARP" in raised letters & a square protrusion to the upper right of the "P". Now look at the space under the hinge where this protrusion would go when the lid is closed.
A little hole. And inside the hole you will find a microswitch (G). Take a paper clip, unbend it, now make an "L" at one end that will let you poke inside the hole.
Screen switches from landscape to portrait when the microswitch is triggered. Which is when the lid is closed down on the keyboard in either orientation. This is why pressing on the hinge causes the screen to return to portrait mode.
I have never taken that part of my C860 apart. If I had the problem, I would try to make a small "hook" to slip under the microswitch activator and attempt to "adjust" it upwards. But there are the obvious hazards to that operation, so do not take this as encouragement for your making the attempt if something bad happens (G).
Good Luck!
