My adapter broke, so I started my repairs by measuring the output voltage; it was 18V as it's supposed to! So, I figured my laptop charging cicruit was broken, but when I opened the adapter I saw the 400V, 120µF capacitor after the main transformer was broken. I replaced it and my laptop was alive again.
I suppose this has something to do when applying a load, but I cannot understand how the capacitor acts in these cases and give me a good voltage reading even though it is blown. Got any good explanation for this?