It's likely to be the same old thing. Bad motherboard. Do try simple like a new CMOS battery. A buck part that for some reason folk overlook.
So my laptop is hp pavilion g7, it's been working for 6 years Today I took it apart to clean it, and put all together, and it's not working anymore! This is not the first time I clean it, I don't know what happened this time
When I boot it, the fan runs at maximum speed for as long as I keep it, the screen does not turn on at all I tried taking off the ram, the behavior was the same!!!
Check this video, nothing attached to the mother board, no ram, no hard drive, no cables, no links. Only the battery and power button, it runs like that, and it's absolutely no differece when I put every connection and every part in the mother board again https://youtu.be/ZEAvjyb-BLU
Please tell me what is that and what should I do.