my graphics card failed so I tried removing it and baking it in the oven after watching you tube videos. Put it all back together and when I switch it back on I get 3 beeps gap and repeating (from what I can see I have replaced all connections). Looked it up and says ”The memory in your Mac didn't pass an integrity check. If you've added or replaced memory, make sure it's installed correctly.”. I have tried removing memory and replacing, still as me issue.. any advice gratefully received.