This chinese all in one computer gives an image when connected to an external vga monitor but only the backlight with integrated monitor (no image). Initially I thought it was an edid problem on the eeprom of the screen but then I saw that the monitor works correctly with another identical motherboard (model th410-d4, read by bios). Unfortunately the motherboard is chinese and has no brand or codes on the pcb. The format seems ITX. Nothing can be found online. The official yashi site provides drivers but not the bios. The electrical diagram is obviously unobtainable
The board is equipped with a chrontel ch7511 chip that converts eDP signals to LVDS and saves the EDID and backlight settings in a giantec GT24C64A eeprom. I think the problem lies with this eeprom but I'm not sure. It could also be the ch7511 chip. In the bios settings there is a menu where you can enable or disable LVDS support. When enabled it returns a submenu where you can choose the monitor resolution, which in my case is 1920x1080. This setting acts on 4 gpio pins of the ch7511 putting them in a high (1) or low (0) state depending on the choice made. Attached you will find the pdf of the eeprom and the ch7511 and some photos of the computer. Where could I start to make a diagnosis??
The board is equipped with a chrontel ch7511 chip that converts eDP signals to LVDS and saves the EDID and backlight settings in a giantec GT24C64A eeprom. I think the problem lies with this eeprom but I'm not sure. It could also be the ch7511 chip. In the bios settings there is a menu where you can enable or disable LVDS support. When enabled it returns a submenu where you can choose the monitor resolution, which in my case is 1920x1080. This setting acts on 4 gpio pins of the ch7511 putting them in a high (1) or low (0) state depending on the choice made. Attached you will find the pdf of the eeprom and the ch7511 and some photos of the computer. Where could I start to make a diagnosis??
Attached Files