PSU, motherboard or hard disk.
Disconnect the hard disk and if it boots fine now, that was the culprit. It's unlikely, but very easy to test.
Since motherboards usually don't make sound, I think the PSU is a likely candidate.
The laptop's power led starts blinking green a few times, then there is a clicking sound and the whole thing turns off. The screen is completely black. Which part could be malfunctioning?

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