At www.kkn.net/~k5tr/ts930fix/w6nl930.pdf you can download the descriptions of some TS-930S repairs and modifications, written by W6NL. The troubleshooting guide for the power supply is there, along with descriptions of fixes for some common failures. It is very easy to follow, so I suggest you to look at it and try to check the power supply. Good luck, Fric YU1WC