Repair - Behringer X32 doesn't boot

May 23, 2017

This article will show you how to repair a Behringer X32 Rack power supply issue that prevents the unit from booting properly.

Disclaimer. Mains Voltage can kill you!

This article contains potentially dangerous content. Please be careful when working with Mains Voltage. Mains Voltage can kill you! I am not responsible if you hurt yourself or others.

Everything you do is at your own risk!

For a couple of months now, my Behringer X32 had some booting issues. By turning the unit off and on again for a couple of times, it would boot properly after some time. So I ignored the issue until yesterday, when the the unit seemed to be completely dead.

Because the unit was working properly after a successful booting process, I suspected a power sequencing problem at first.

Inside the Behringer X32 Rack, the PSU is on a separate PCB in the right front. To take it out, four screws have to be removed.

Behringer X32 Rack with open enclosure

Before I started with the repair, I tried to find a service manual for the behringer X32 Rack, but I could only find one for the regular Behringer X32 mixing console. Although the PSU in the rack version seems to be different, the processor board is the same. This is helpful because now I know what the voltages going to the processorbord should be.

As far as i know the voltages should be as follow:

Behringer X32 Rack PSU output voltages broken

Because the voltages are all low by about 30%, the problem is likely to be caused by the feedback loop for the control circuit of the flyback converter.

BehringerX32 PSU Sector.jpg BehringerX32 PSU Sector back.jpg

A common issue with this type of power supply is the degradation over time of an electrolytic capacitor in the control circuit of the PSU. This leads to a decreased output voltag or prevents the PSU from turning properly on at all.

After locating this capacitor, I replaced it with a new one. In this case it was an 47µF / 35V.

Behringer X32 PSU Bad capacitor

After replacing the capacitor, the output voltages were as follow:

So the voltages are still a bit (10%) to low, but much better than before.

After a while thinking about that, I decided to give it a try and tested the PSU together with the rest of the X32.

And it worked. Now it only has to be assembled again.

Behringer X32 Working