reel/stop button isses

[davey400]

I will try to explain:

The input power on the board will be routed through some other components (fuse, resistors, diode) to a 7805 series IC, which functions as a voltage regulator; it reduces the incoming 24 volts to 5 volt, which is used on a large part of the board.
The packaging looks like a transistor. Looking at this formfactor you can see it is not being cooled, so it will not be designed to handle very high currents.

The board does not know if the input voltage is always clean, and to protect the rest of the circuits on the board it will try to 'clean' the incoming power.
It does so in 3 ways:

There is a big capacitor; that stabilizes the incoming voltage. If there are short drops, they will be compensated by the capacitor. Even short peaks will be leveled down by that capacitor, the big blue tube on the lower left at the board.
Than there is our famous C10. This is supposed to eliminate high-frequency disturbance, if any.
Finally there is a 27 volt zener-diode. If the incoming voltage is higher than 27v, this will short-circuit and therefore blow the fuse.

The problem with C10 in my case was that this component was causing a short-circuit. This also causes the fuse to blow.
Since the incoming voltage is expected to be clean (and seems to be clean in my case) there is no need for C10 to filter any disturbances.

Having the C10 is good; always expect the unexpected.
That's what the designer of this board did: "I am not sure I will get a clean input power, so let's make it clean before we use it".

But the designers of the rest of the components did the same: "Let's make sure that my components work perfect!", so they created a clean 24 volts power source to be used by other components.

So is it better to replace C10 with a working one: Yes. Because it is supposed to be there, and just in case the input is not clean.
Is it essential for the working of the board: No, as long the incoming 24 volts is not messy.

I hope this explains my thoughts about leaving out C10 (for now...) a little better.
I will replace it one day, I am just not in a hurry to do so.