Behringer X1222USB audio mixer Power Supply fails, again!
The SMPS modules fitted to these Behringer audio mixers are crap!
Fault symptoms include the appearance of no power to the mixer, except for the +48V LED being faintly lit when phantom power is turned on.
Adam explains what he did in this video:
D6, a HER303 ultra fast diode was found to be short circuit.
Electrolytics C6 and C9 were starting to bulge and were replaced.
A schematic for a similar SMPS was found.
This is not exactly the same, and differs around the 48 V regulator.
All other components have the same designators and values however.
Use this diagram to determine what the PSU connector cable nominal voltage rails should be;
With a previous repair, electrolytics C12 and C16 (1000 uF 25V) were found to be bulging and replaced.