display problems, builtin dispaly not showing external display working
iMac 21.5 late 2012 slim type model A1418
Hi guys I am completely new to this forum and hopeful to find answer with what's going on with my imac, the story begins..... I recently try to upgrade my iMac ram following the instructions here, I tried installing new ram and was working fine, then I tried add additional ram and was working fine as well, the third time I tried to lift the LCD I forget about the lvds cable and unintentionally pull it, I did not worry at that time, so then when I insert the lvds and tried to turn on my iMac I can hear boot chime but without display, I tried with external display and as expected there is display showing, I carefully inspect the lvds cable and found out that some contacts are broken (not visible because it's tiny) so what I did next is order similar cable and as I received the cable with no luck still without display not even LCD lights, I was desperate and look for I fix branch here in philippines and I told them the whole story, and they said that it could be the LCD display, and if I already did the troubleshooting it's no sense that they will repeat the same procedures and pay them for nothing, so I order new LCD panel, exactly the same model, and couple of lvds cables just in case, as I received the display LCD I replaced and with new lvds as well, but still without any luck, looking for some advice guys maybe you could recommend much deeper troubleshootings to fix my machine, maybe some fuses imbedded on the logic board for display, but I do not know where to find such fuses I am not familiar with this tiny electronics but I know basic troubleshooting with multimeter, I would really appreciate if somebody could give me a guide how to locate suspected fuses, also LEDs light are working except for the no. 4 led which I believed responsible for LCD communication, thanks you guys and more power.