What is broken? No display and Power / Fn buttons flickering
I'm asking because I've never encountered these symptoms with any computer ever before.
- flickering power and Fn buttons
- laptop screen blank
I replaced the mainboard of my X270 with one bought from a Chinese store. I've done that before on other laptops of the same model and with different models. although no professional hardware technician, I'm familiar with that kind of work.
I installed the replacement and booted up. The symptoms are as described above; the laptop screen is staying blank and the power and Fn buttons are flickering. Not blinking, flickering. This does not at all look like a post error blinking, it's way too fast.
The flickering might have a pattern that repeats after a pause, but that's just a feeling and I first need to actually record the timings.
With an external screen attached, the system can be used fine, but the flickering of the power button persists.
It's a very weird error. Do you have any clue about what could be broken and how does it cause the symptoms. Or are they unrelated?
I rechecked the flickering of the Power and Fn buttons; there is a pattern and it's five flashes in about 0.5s, every 1s.