It is clear that I can use a capacitor with a higher voltage, but this time I have to repair a LAPTOP POWER SUPPLY. I have the problem that two capacitors with 680 uf and 25v are built in here. I don't have these in stock at the moment. Can I actually use a smaller value (470uf and 25V) or a larger one (1000uf and 25V) or can this already lead to a problem? LG Leo
I would take the bigger one. A little more current can flow when the device is switched on, but that happens when the capacitor is charged. (Please don't sue me if something else breaks because of it.)
In the case of a smaller capacitor, the AC voltage component would be larger and interfere. But that would probably also be possible.
It's not that easy to say. It depends on what the electrolytic capacitor does exactly, if it is only for smoothing, a bigger one would not be bad if it belongs to the stage of the voltage converter, something changes starting from e.g. The clock. In the second case I would start with the smaller one and measure what comes out under load. If you have enough space, you can also make a series or parallel connection. In addition, the tolerance for capacitors is normal at 10 - 20%, which means that the built-in one can also have about 550 uf and the 470 can also have 560 uf.
The capacitance values must match. The dielectric strength (25V) can also be higher.
I recommend Ultra Low ESR types for this. These cost a little more, but they have a longer lifespan.
