Behringer Truth B2031A Active speakers appear to lose power or cut out after 4-5mins playing time. Both speakers are affected but not exactly simultaneously. Is this a recognizable fixable problem?

I got it fixed for 2 weeks now. All I had to do is to put two small heat sink on the 78xx and 79xx TO220 regulators. It still is a sign that something else is failing, but it does the trick for now.

I had the same problem and when I switched the "Power Mode" switch on the back to "On" rather than "Auto", they worked just fine. I hope this is helpful! 

Jevan50 thank you so much for posting! Same exact issue one speaker. The 7915 was at fault and my original part was a ML7915A by Micro Electronics. It has their logo on it. Here is what my volt meter showed:

Before the dropout, voltage is as follows:

7915A - Pin 2: -33.3V, Pin 3: -14.9V. (Pin 1 is ground)

7815A - Pin 1: +34.1V, Pin 3: +15.0V. (Pin 2 is ground)

After the dropout:

7915A - Pin 2: -39.3V, Pin3: -0.8V.

7815A - Pin 1: +32.8V, Pin 3: +14.9V.

As you can see the 7915 lost voltage on the out PIn 3. You can google spec sheets on all of these. I found a replacement part from Parts Express part #7915 which was a LM7915C for 75 cents. I got a couple and some 7815's just in case. Don't know the manufacturer, I couldn't match the logo. But it has a metal heat sink, unlike the original plastic one. Don't forget to get some thermal paste, as you will have to remove the three chips that are bolted to the main heat sink in order to get access to the 7915 solder points. And yes, not so easy removing and re-soldering a part that has 3 solder points. But this has saved me so much time and money. And sorry to say, you get what you pay for... (I also have the known radio interference with these monitors, but is very slight)

Thanks again jevon50, you're a genius!

Maybe problem in cabels

Where did you buy the regulators

About the RADIO INTERFERENCE... If you remove the plug from the speaker cabinet to the circuit board that operates the power and Overload LEDs, it will remove the interference. I blacked out my LEDs with a magic marker before I made this mod, so not having the LEDs function isn't a problem for me. I find most LEDs (especially the blue ones) super annoying. Remove the plug, and you will no longer have to put up wit unwanted Lady Gaga music bleeding through.

I have the same issue, sound cuts out after 3-5 mins, it does seem to be those two regulators getting a little hot, ive put heatsinks on them and it has been fine for weeks...

I have the same problem and reckon jevon has the correct solution as I monitored the output voltage of the negative regulator and it dropped to near zero when the unit switched to 'overload' . A couple of quick questions please jevon.

Did the heatsink solution work totally , or is replacing the regulators the only way forward?
Did you replace then with 1 amp or 2 amp regulators.

Thanks in advance

I have one that does the same thing, when it warms up, the red "overload" light goes on, the woofer thumps, and that's the end of the sound. Turn it off and then on and it takes about 15-20 seconds to thunp and go off again, but when it hasn't been turned on for a long time, it takes about 5 minutes; obviously something is getting hot, I wish I knew what so I could replace it.

Bord problem

Hey, i have one of my B2031A's a little far from the AC and the sub just goes off after every while and i have to give it 10-20 min to reset other wise the sub doesn't come back now, it has completely gone off and only the highs are working i saved money to get them and now one of them is sh**ing up looks like the germans need a little lesson in audio, plus there is no circuit diags available which is really, really Sad.