Q: mac not starting up

Intel-based Mac Power On Self Test RAM error beeps

Power On Self-Test Beep Definition - Part 2

Means you have a problem with your RAM. Either it has failed or the slots have failed. The "idiot guide?" Take it in for service.

It typically means that the memory modules installed are non-functional. This could be because the memory modules have failed or the slots in which they are installed have failed or the motherboard has failed. Usually, the problem is with the memory modules which are easily replaced. But if it's not the memory modules then the problem is more difficult and more expensive to repair.

It can't hurt to move the modules to the empty slots. Look in your user manual section on Adding Memory to see how you install memory.