Recapping A Board With Different Capicitance Caps?

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Re: Recapping A Board With Different Capicitance Caps?

The way I see it, the capacitance and the voltage have to be exact if you want the best performance.

But since the majority of the electrolytics in your equipment will probably prove to have 20% tolerance, that all goes out the window.

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Re: Recapping A Board With Different Capicitance Caps?

Something else not yet mentioned. If you start replacing (as per this thread example) 1000uF cans with 3300uF, after having replaced several you then have a much larger inrush current and a longer delay in reaching the target voltage. This has been observed to be detrimental enough to keep a motherboard from posting.

I often (actually prefer to) use a larger cap than the original when it will fit and that often means higher capacitance, but to avoid the situation I mentioned above I also move up to the next voltage rating. For this example (of a 6.3V / 1000uF replaced by 6.3V / 3300uF) I would use a 10V or 16V part instead at 2200uF or less instead of more than tripling the capacitance.

This is all within the context of the factors PeteS in CA mentioned already but with the addition that I've never caused control loop instability when I did exceed 150% and I do that fairly often. Not saying it's impossible and the controller itself could also have the same issue with an internal shutdown function if it can't regulate the output quickly enough due to the increased capacitance.