I’ve been trying to estimate a RBC model with Dynare but my model don’t converge and f(x) stay around 0.26. Being a new dynare’ user I think i made some mistakes in my .mod file. I hope i could find some useful advices here.

I am not sure, what can I tell you… I do not do much estimations my self. I calibrate my models but I use fsolve - myself, not via Dynare - to estimate the steady-state values. Make sure that the problem is stationary and well defined. Make sure that there are no unit roots. Some parameter values are sometimes associated to unit roots. Make sure that this is not your case. My other guess would be to try different initial conditions but you already did that…
Good luck!

resid(1);
before steady and trace down the residuals. Either your steady state computation is wrong or the entered model equations. Currently there are large residuals suggesting that did a mistake somewhere.