Almost certain you during the assembly have forgotten to insulate TR27 - the transistor that uses the bracket - shilding the big electrolytes - as a cooling plate. Its fastened to the bracked by a small bolt. If not insulated properly the whole unit will be none working including the small red power led.
Its very easy to miss the insulation - a small square plate insulates the transistor from the bracket AND - a very small plastic washer - insulates the bolt from the transistor - so that the transistor will be perfect insulatet from the bracket. The TR27 might survive the miss treatment and also the whole unit.
