Starting up just the 'naked' logicboard
I have a logicboard laying around and would like to test / verify it's functionality.
In my test case, there is following connected to the board:
- Screen-Adapter (for getting some feedback)
- Speaker, left (for getting some feedback)
- RAM (optionally, to trigger "RAM Missing" beeps)
- HDD (optionally, to trigger some Disk-Access)
Two things happen, when the Charger is plugged in:
- Fan begins to start automatically, runs continuously. The fan runs quite silent/slow
- When the Keyboard is attached and the power button is held, nothing happens until button is released. Than the fan begins to run at maximum.
As I know this from working devices, this seems to be the the step before going to normal boot sequence.
Is this behavior already the result of a broken board?
Or is anything mandatory missing?