This article explains how to eliminate ground loops in your audio system setup. Ground loops are usually perceived as a hum or buzz in your audio signal. This can be caused by devices that introduce an electric potential to the ground connection, including peripheral devices connected to your computer. Note: If you are a TRAKTOR Scratch turntable DJ, make sure to connect the grounding cable on the back of your turntable with the grounding screw on the back of your audio interface or hardware mixer. If either grounding cable or grounding screw are not provided, please consult the manufacturer of your hardware device for more information. With this in mind, the following points should help to eliminate the ground loop: A low quality power supply unit can lead to ground loop noise, particularly on laptops. Disconnect your computer from your power suppy so that it runs on AC power and verify if this resolves the issue. If you are going to use a replacement power supply unit, make sure that its specifications meet the ones required by your computer in order to avoid permanent damage.

Always connect your devices to the same power outlet (e.g. with a multi-outlet power strip). Note that even if the power supply of your laptop computer is not connected, your setup may still be vulnerable to ground noise from an external device with its own power supply. All devices that are physically connected to each other should share the same power outlet. You may also have to separate polarized plugs (two-prong) from grounded plugs (three prong), by connecting them to separate circuits. In order to find out where the ground loop arises, disconnect all devices from your computer and / or mixer, but not the amplifier and / or speakers. This also applies to other peripheral devices you may have connected to your computer (external data storage, CD burners). To check if the amplifier or active monitors create the ground loop, monitor your audio signal from the headphones output of your audio device (while the amplifier/active monitors are disconnected). If you find the device that introduces the ground loop, a ground lift of the audio connection may solve the issue.

Never lift the ground of the power connection! Note: Contact the manufacturer of your device before lifting the ground to find out if ground lifting is supported on your device. ruud hvac unitSome devices offer a switch for this whereas others may require a modified audio cable or a DI-Box (see below).hire portable air conditioning units uk If possible, always use balanced audio cables to connect your audio device to your mixer or speakers. coleman mobile home air conditioning unitsIf your mixer provides both unbalanced and balanced inputs, always connect your balanced sources to the respective inputs on the mixer. If you cannot fix the ground loop with the tips above, you can try to put DI boxes in between the connections of your audio devices, your mixer and/or your active loudspeakers.

This will break the ground of the audio connection. With a DI box you can use balanced audio cables for unbalanced audio sources. Additionally, most of these Di boxes feature a Ground Lift switch. Last year my home's central air condenser fan motor stopped working. When I noticed the house wasn't cooling down I went outside to investigate and found there was a humming sound coming from the unit, but the fan wasn't turning. After researching the problem online, I found the capacitor may be bad and causing the problem. The capacitor wasn't blown, but I replaced it anyways. The problem still existed; Fan won't spin and a humming sound is coming from the unit. So, I inferred that the motor must be bad. Yesterday I unbolted the fan from the unit to try and spin the blades by hand. To my surprise, it spun. It spun 3 to 5 rotations with a medium amount of force (the same force it would take to bounce a basketball 8 feet in the air). I expected the motor to be stuck and not spin at all, so now I'm second guessing myself.

My question is: How freely should it spin? I've read in numerous places that the blade should spin "freely", but I'm not sure what that means. Should it spin around 50 times with a medium amount of force? If I was holding it up in the air, should a 15mph breeze spin the blades like a pinwheel? Or is the 3-5 rotations freely? If you replaced the start capacitor, and you are getting proper voltage to the fan motor than the only thing left is to replace the fan motor. If the fan turns at all without forcing, it should spin when powered up. If the fan turns freely or not is not a definitive indication that is good or bad. It should spin freely... I looked at neighbor's condenser fan and they all spin freely with very slight force. However how a motor spins isn't necessarily indicator of whether it works or not. A coil could have shorted or insulation burnt. You can test this by taking an ohmmeter, one lead to the motor leads, and the other to the case. If there's continuity between the leads and the motor casing, it's bad (and in fact sometimes it should blow breakers too).

You can also read the resistance of the motor leads, if it's too low then there's a short between the windings. Basically a good fan should spin at least half a revolution with the amount of force it takes to lift a sheet of paper. I'm far from being a HVAC person, but I do like to figure things out on my own. I had the same thing happen and before you order a $300 part, all I did was take it apart and clean it really well. I used graphite lubricant on the blades and 3-in-1 on the shaft of the motor and guess what?!! It puuuurs now ;) if u change the capacitor and does not work turn the power on use a screwdriver and try turning the fan you will notice motor making a buzzing sound and hard to turn just replace motor.I had the same problem and that took care of it.Two more things your motor may have three wire black brown and orange today motor have five wire instruction come with it connect the two extra wire together with a wire nut and wrap it with some electrical tape.Last i recommend u change your contact switch because when your motor start going bad it spark more and more as the motor life coming to an end.