Chosen Solution
Hello to all, I have problem with Acer Aspire 5520. Laptop is working only on external display connected on VGA port but internal screen don’t show anything, no backlight, not even picture under the light on that screen. I have try with another motherboard-screen flat cable, also have tried another panel, light inverter but nothing showed, dead. Computer boot and work fine on VGA connected monitor but on internal nothing show up from powering on pc- bios - windows, nothing. Internal monitor also not detected in windows, when I open graphical properties there is no second screen only one (VGA monitor), so there is no option only second scree or similar, one screen is available only. We can skip suggestion like reinstall drivers, FN key for monitor change, hold power off without battery and that kind of stuff or similar because BIOS is not showing on the internal screen. RAM, HDD, are tested and 100% working. Any suggestions?
Hi @shule88 , I don’t know the answer but here’s a link to the motherboard schematics. At least I think that it is the correct one. Check the motherboard’s board number (printed on motherboard) to verify. On p.2 the circuit block diagram shows how the internal screen (LVDS) and external screen (CRT) connect back to the chipset IC On p.7 it shows how the video signals and controls are sent from different sections of the chipset IC (see LVDS and DAC sections) Something is telling it not to connect video from the LVDS section of the IC but from the DAC section is OK. I don’t know enough about how chipsets function down at this level though to know how it switches between the outputs I realize that you said not to reinstall the drivers but have you checked that the chipset drivers (supplier example only) are OK and are the latest available, just in case? I would also try removing the cmos battery (soldered on board top right hand corner) and removing the main battery and then doing a hard reset as a corrupted setting may be being held in BIOS by it and preventing the switch over of the outputs from the chipset. You haven’t got much to lose by trying everything first before delving into board level repairs Otherwise you may have to check the components and power supplies around the chipset IC (also see p.19) Just what I would try.
