The SWB10 bridge rectifier converts AC voltage into DC. Check for AC on the ~ terminals and DC on the +/- terminals. Usually these short when they fail passing AC through to the output. Occasionally they will fail open but not often. It's probably the fuse that failed. Make sure you use the exact replacement so nothing gets damaged.
Also check resistance across the +/- side of the rectifier with power removed. This will show if anything is shorted by swapping the polarity of the leads. There may be something shorted downstream from the power section. Unplug the power supply outputs if there is a connector. Then you can tell if it's the supply or the load causing the problem.
Sorry I didn't post on the Vintage Synth site. I don't have an account. Suppose I could create one if necessary....
Fran - Moderator