There are 3 power supplies on a bb1 cabinet. The one on the photo is the 24 volt power supply. Then there's a HUGE transformer at the rear right bottom inside a silver box, that's 15v, and then there's the ATX type power supply on the right side bottom of the cabinet just in front of the 15v transformer silver box. You can see which voltages are not being provided. There are 5 leds as shown in photo. Make sure they are all lit and not blinking. Whatever is missing, is the one you need to check on. 3v,5v,12v are all supplied by the ATX type power supply. 24v by the one below the amp, the one you pictured. 15v is the transformer in the rear.