Hello. I got in a Lenovo g480 that was being used with a generic adaptor that I can not verify since they threw it away. The laptop will not start (now with the original adaptor). When pressing the power button the power light and webcam light comes on, plus the fan spins, then after about 1-2 seconds it all powers off, then back on again. This goes on in a loop. The only visual damage I could find was one transistor pq3801, it was fried. But after replacing, it does the exact same thing. It seems that transistor is only to turn off the power if needed, so it shouldn't cause this symptom.
The board model is lg4858. I have been over the schematic and I have found all voltages except for the gfx voltage. But from my experience, a missing gfx voltage does not make the computer try to keep booting like this.
I have also tried flashing the bios from a usb with the fn+r keys. When doing so, the computer stays on, with a blank screen for about 2 minutes, shuts off, then reboots to the exact same problem. Does the laptop check the bios to make sure it is the correct one? It was downloaded from the lenovo webpage, and extracted from the exe file.
Any ideas?
The board model is lg4858. I have been over the schematic and I have found all voltages except for the gfx voltage. But from my experience, a missing gfx voltage does not make the computer try to keep booting like this.
I have also tried flashing the bios from a usb with the fn+r keys. When doing so, the computer stays on, with a blank screen for about 2 minutes, shuts off, then reboots to the exact same problem. Does the laptop check the bios to make sure it is the correct one? It was downloaded from the lenovo webpage, and extracted from the exe file.
Any ideas?
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