I found abandoned IBM Thinkpad 560X inside of company's cabinet. So, I got curious and get generic AC-DC SMPS adapter for 10$. It was rated 16V 3.75A, diameter for plug is just right, and polarity was center plus. Just like laptop wants.(560X required 16V 1.9A) According to that, it should work.
But when I connected adapter to laptop, it doesn't power up. Plus, adapter's power indicator LED doesn't stay on. It was doing kinda flickering, but very faintly.
I got freaked out, and disconnected it from laptop. After that adapter's indicator LED was lit steady. Plug in to laptop again, and still flickering.
I can't understand why this happening. Usually flashing indicator LED means that PSU is struggling to push power into device, but in this case, PSU is 60W, and 560X requires about 30W. There's plenty room for wattage.
Is it SMPS adapter laptop wants? Or laptop power adapter is different from generic SMPS adapter?