I bought an electrostatic furnace filter pad. It s just a sheet of material that need to be cut to the size of the air...

I have a Macbook Air mid-2013 model with the same problem. I dropped it and now the display just gives me colourful vertical lines and I cannot use the thunderbolt port for external displays. However, initially after the drop, video output to external displays was working for a few hours. Then it stopped working and I brought it to a shop who did something which got it working again for a few days and now it's not working. I don't care about getting the internal display to work - I just want to get video output to external displays working. I'm not sure how to locate the GPU to try this "heating" method described here... could someone please tell me how to find this chip? I've googled it in many ways but to no avail...