Laptop disassembled, no beeps, no post (black screen), only led's and fan spins for 3 sec, motherboard malfunction?

SmoothLemon

Honorable
Jan 4, 2013
5
0
10,510
I disassembled a laptop, and connected it without it's case. No beeps, no screen, even with external monitor, only led turned on and fan spins for cca 3sec then stops. Are these symptoms diagnosed with motherboard malfunction?