2.6KV 100UF capacitor, is there any way to repair the capacity?

[daisizhou]

I don't know why the capacitance of this capacitor always decreases.
I used an LCR meter to test the capacitance and found that their capacitance values ​​were all less than 96.5uf.

I took one apart and checked the inside and found no dielectric oil.It looks like it's the dry type.
If you know how to improve it, please let me know, thanks

[NiHaoMike]

Looks like degradation from being operated near or above rated voltage. (So called "self healing" dielectric.) No practical fix, but if you derate the voltage, it would avoid further degradation.

[amyk]

2.6kV 100uF? Are these from a microwave oven being operated on slightly higher mains than it was rated for (240V instead of 220V?)

[daisizhou]

 ;)It comes from inside the philips m3536a.Normally the voltage will not be higher than the maximum rated voltage value marked.

What is incomprehensible is that the capacitor is damaged.

As far as I can remember, this type of capacitor is usually an oil-immersed metal case capacitor.The insulating oil is added last and the filling port is sealed with tin.