I don't know what method you used to make the conversion. Method 1 is RJ's where you connect the two sides with the jumper points in the center of the board. If you used this method then make sure that your solder connections are solid and don't forget that you have to make jumpers for both the hot and common traces. The hot jumper points are above the triacs and the common jumper points are on the bottom of the board below the output strip. When this method is used the fuse on the right is not needed and should be removed.
The other method is one that some of the members came up with to make it easy to convert the board back to dual input when needed and that one is to simply connect the two sides together with jumpers at the AC IN wire connections. If you use this method then once again, make sure that your connections are good and in this case, the right fuse is still needed so make sure that it is seated properly and is good.
The best place to measure is where you made your jump to the other side and make sure to test both the hot and common sides. Also check the traces on the bottom of the board for any damage near your jump points. These are large traces but are not immune to damage.