Fan mod almost done - Electrician help needed

[Vento]

As title I've almost completed a mod to add a small fan on top of the router (image) (a TD-W8970 v1), which comes already with a small heat-spreader (I've also added some others) but I do not think that's enough (really I've touched it and it's almost scorching).

I've took the exposed wires of the fan and made contact directly with the small power supply and the fan is enough fast and completely silent. Now I should solder everything but I'm not completely sure about where... The perfect (my electrician knowledge is limited, I'm more a software/algorithms/security guy) thing would be to figure out how the power button works and hookup one wire there and one directly where the power supply is...

if needed I can provide PCB photos and even poke around with a multimeter.

[mbo2o]

Just use a seperate power supply for the fan.
You don't need to wire directly to the router

[Vento]

Yes I could do that but having everything inside the router would be nicer

[mbo2o]

In that case, first make sure that the total wattage of the fan and router is less than that of your router's power supply.

[Vento]

Done it! Ground to power connector and +12 volt from main power button pins Also it works only when the button is pressed (as expected). Video just for fun: https://streamable.com/bul3e