The red paste is used to mechanically fix the integrated circuits to the board. If you remove it, you can damage the connections.
At this point, everything indicates a problem with the board. If it helps, I have a laptop (from which I am writing this) that had numerous hardware problems and sometimes the computer wouldn't even start up. All the problems were caused by the network chip. I finally removed it (in a rather unorthodox way) and from that moment on it worked perfectly.
Removing integrated circuits soldered to the board is very dangerous in the sense that once removed, the computer most likely will never turn on again. On the other hand, you have to be completely sure which device is causing the problem.
In this thread you have the follow-up of the problem.
Finally, if it's a matter of "either I fix it or it's useless to me", you can try this. You might be lucky.