Behringer B2031A monitors playing quietly and distorted

[Magma828]

I was given a pair of broken studio monitors, and I'm trying to repair them. They sound very quiet and distorted. Is it likely that there's a problem with the woofers/tweeters, or some component on the PCB? And if it's a PCB component, which is it most likely to be? Based on the fact that I can still hear something.

The main parts are 2 big electrolytic capacitors (6800uF/50V), 3 amplifier ICs (LM3886T), and two voltage regulators (7915A and 7815A). Nothing looks burnt out.

I read somewhere that the amp ICs often overheat and need replacing, but read somewhere else that they're bomb-proof and hard to damage even when trying.

I also read a post here where someone said capacitors can cause strange behaviour. Does this sound like a capacitor problem?

I've also had a look for broken solder joints but can't see any.

[BertKoor]

Without special testing equipment it's hard to locate the blown component. I'd bet on a semiconductor. Low volume & distortion sounds like the power amp isn't getting the voltage it needs. With a multimeter you can test how much they output, and compare it to what they should deliver. You need good soldering skills and good tools to remove the solder. If you can obtain these chips for a low price, it's definitely worth a try.

With a simple multimeter it's possible to test the capacitors to some extent: measure the resistance and the figure will rise over time. Swap poles and you'll see movement again.

Imho your best bet is to "convert" these to passive speakers, and get a cheap power amp (100W per channel) to drive them.

[quino]

did anybody actually find a fix for this? got a free broken speaker as weel, same model, and same problem, quiet and very distorted