AnsweredAssumed Answered

Display with PTN3460I sometimes not work

Question asked by Michael Spaeth on Nov 6, 2019
Latest reply on Nov 14, 2019 by Michael Spaeth


we have the problem that some of our devices (WIN10 embedded) arbitrarily the internal display on the PTN3460I stays dark and is not found in WIN. If I make an update of the graphics driver (with external monitor possible), then the previously not found internal display works without restarting. Does anyone have a similar problem or can I give tips on what to look for?

During the investigation, I wanted to read the register contents of the PTN3460I and have a strange behavior here. We operate the PTN3460I on an Intel Atom E3800 CPU. The I2C interface is controlled by a dedicated board controller.

From this, initially only register 0x84 (EDID ROM emulation control) is written. If I now read back all register contents, the value 0x00 is in register 0x81 (LVDS interface control 1). The default value according to the Programming Guide (AN11606) should be 0x0B. All other register contents are correct. Even if I explicitly write 0x0B into the register, I read out 0x00 afterwards. If I write 0xFF into the register, I will read 0xC7 afterwards. What is going wrong here?

Please help me!

Thanks in advance,