LED blinking 1,4 in Precision 7750

Hi, does someone knows what's the reason my laptop is blinking the LED 1 white 4 Amber?

When this happens windows gets really slow and irresponsive, and if it's not connected to an outlet the computers just shut off.

Computer is not mine but for the company I work for, I took it once to the IT support and they said they would change the motherboard which I guess they did it because it worked fine for some time but then again issue is present.