Gemsound power speaker pxa105

I would check the caps on the power supply. They are rather large electrolytic capacitors that will look like they burst and/or leaking. When these die, the caps ground and the sub will make a loud buzzing sound. If you are handy with a soldering iron you can replace them yourself. Replace them with the same voltage or a little bigger and same with the size.

If the cap. says 16v 4700pF on it, for example, a 20v 5300pF or a 16v 6200mF cap. will work for this application.

Possibly a bad cable or bad ground or bad outlet?. Easy solution, try a different outlet and see if the hum still exists. Also, make sure your speaker cables are NOT run parallel along with, or close to any power cables, Speaker wires can and will pick up AC "Humm" noise.

check your audio line in connection, either L or R signal line floating may also cause humming noise. Sub woofer usually very sensitive. If your audio input not connected, do you still hear humming noise? in actual you should not hear such noise, unless volume at max then it is possible to hear little.

Hello
Switch on your amp, keep its volue down to extreme low, and listen if there is still hum through the left channel or not. If still there is hum, the left side power amplifier section inside the amp;ifier is faulty. If htere is no hum at this state, hum enters thorugh the audio input terminal, and the input wires must be checked for open sheild connection. OK.

If I understand this correctly: with NO input or cable attached it hums; with an RCA cable attached it works. (What does 'some' mean in this regard?)

You say that connecting the RCA cable improves its sound. That tells me you're supplying a ground through the RCA cable for stray voltage in the sub.

It seems there may be a basic power issue if it hums with no input. Sometimes a given power source in a home may be wired differently than others or may insufficient grounding, which can result in hum. Try reversing the sub's power plug or move it somewhere else.

Since the sub contains its own electronics it is also susceptible to strong external magnetic fields. Keep it and any signal cables leading to it some distance away from other electrical devices like TV's.

verify all connectons, make sure you don't have something crossed.

Likely the power adapter has failed if it uses one. Try a new one first.

If half the rectifier blows out, a very impure DC voltage is applied which will be heard in the audio output.

have no idea but what kinda speaker is it for a car or a house if for a car then u might have hooked it up wrong or the coil is blown hopes this helps

Yes that noise is causing your fuse to blow. Machine gun sound sounds like the High Voltage Capacitor or High voltage diode is bad. (Loud humming sound is usually a bad magnetron or bad power transformer). Most of these parts are inexpensive, except for the magnetron. But most of the repair bill is most likely going to be for labor.

Based on your model, it looks like an over the range microwave. And to fix any of these problems require the removal of the microwave from the wall. So its up to you if you want to deal with that hassle. But you also have to consider that you'll probably have a hard time trying to find a new microwave that will fit.

try another speaker on that channel if you get no sound or it hums then it is time to take your set to a tech your audio out put on that side is damage along with some caps.good luck.