replacing capacitor

[mensahotoo]

will it be appropriate replacing a 100uf/450v capacitor with a 450uf/200v

[helius]

That depends entirely on the circuit in which it is a component.
We can generally expect that if a 450V working voltage capacitor was originally used, it was because that rating was considered necessary for proper circuit function. If that is the case, a 200V rated replacement would not operate properly and could fail explosively.
Replacing a capacitor with a 4x higher capacitance is also unlikely to function as originally designed, although there are some circuits in which it would be acceptable. You have not provided enough information.

[mensahotoo]

the power capacitor is in a smart tv (NASCO 42" smart tv).

[Jono427]

Should probably just replace with a cap of the exact same rating.  There is probably a reason they are using that one.  If you post the model number of the TV and pictures of the board maybe someone can look and see.

[4thDoctorWhoFan]

Don't do it.  You are just asking for trouble, especially in a TV.
Replace the capacitor with another 450V capacitor.  I also would not go higher than about 220uF.
You should just get an exact replacement.

[ollihd]

When replacing TV caps you should 99% of the time replace the cap with a cap of the same capacitance value. The voltage can be equal to the original or higher, not lower. I usually order the same exact one I'm replacing (same capacitance value, same voltage rating, same temp rating, same manufacturer). The more special characteristics of caps play even a higher role when talking about audio circuits. Hope this helps!

[mensahotoo]

thank you all

[james_s]

This is one of those cases where if you have to ask, then no, you can't. I think it has already been covered but you generally have a fair bit of wiggle room with the capacitance but the voltage of the replacement must be equal or greater than that of the original. Sometimes you don't want to go *too* much greater because higher voltage caps tend to have higher ESR and are physically larger. For example if you need a 16V capacitor you probably don't want to use a 250V capacitor but a 25 or 35V rated part would be fine.