You can replace with a cap rated higher voltage, but not lower. So 16V cap would be unacceptable. Replacing 470 with 680 is almost a 50% increase. Look for a 470uF with 25V or higher rating. If you can see the tolerance on the old cap, or in the parts specifications, then you could go up or down on the uF if you remain within that tolerance. For instance, if the old cap is 470uF + or - 20%, then you could install a cap measuring between 376uF to 563uF.

Since the cap is to filter the 5VDC, a cap rated at 16V should be adequate. The usual rule of thumb is to use a cap that is 3X the voltage anticipated.
I know this differs with JethroP but I think it will be OK.

Also, 470uf isn't really magic here. Other game systems from Williams and Gottlieb used a 100uf cap for the same purpose.
I would not use a cap of greater than 470uf, but anywhere between 100 and 470 should be OK.
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Chris Hibler - CARGPB #31
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