Troubleshooting without tools is difficult, unless you measure voltages with your tongue
If the blue cap is charged, than the primary side should be ok; try to find out if the secondary side is ok.
If you don't have any Multimeter, you can short the caps with a screwdriver;
shortly after the Board was switched off!
It's stress for the caps if they are discharged by a short, but it should't damage them if you do it only a few times.