# Substituting capacitors

I have a nicely-spec'd wireless router that doesn't work any more. (Sorry, I don't have a schematic, but it's an Asus RT-N16.) I popped it open and found that it has one capacitor with a bulging top. It's labeled 16V 680uf, but I don't have a capacitor with those exact specs. But as long as I find another capacitor with roughly the same capacitance, I should be able to substitute that, right?

Q=CV
Q=16v*680uf
Q=10880C


I have a ton of random junk that has various capacitors with other specs. For example, one is labeled 35v 470uf.

So, suppose I want to substitute this 35v capacitor.

C=Q/V
C=10880C/35v
C=311uf


Since the proposed substitute capacitor's 470uf > 311uf, is it likely that this substitution will work, or is it the case that I'm oversimplifying this and need to find something with closer specs printed on the side?

The voltage is the maximum the capacitor can withstand before the dielectric breaks down, and does not factor into the capacitance (measured in farads, $F$). Use a capacitor with the same capacitance, and the same or higher voltage rating.
Also, $Q$ is charge, and although it is the product of voltage and capacitance, you must use the applied voltage, not the rated.