Chosen Solution
The notebook hp pavilion dv6700 p/n FF761EA#ACB doesn’t start when its stock power supply is used. When another power supply (in fact powerbank) with larger maximum current and the same voltage is used, it starts and works (no longer than powerbank battery can provide, about 30 minutes). It doesn’t work with another new power supply equivalent to stock. It is possible to use it with more powerful power supply, but it seems to be dangerous because more current means more power and more power means more heat, so the problem should be found and fixed.
@kolanich the original power supply has an output of DC 18.5V, 4.9A, 90W How much does your “other " power supply have? Your higher wattage could be okay, depending on by how much it is higher. My first thought here is that your power supply no longer supplies what it should. Check that one first.
