My KC550 just suddenly stopped working. What steps do I need to take in order to get this fixed?

It's possible that your Marshall MG30 DFX amplifier is experiencing a hardware issue. The noise you're hearing when you turn it on and off could be caused by a malfunctioning component in the amp's power supply or switching circuit. Similarly, the intermittent operation of the channel switch could be caused by a problem with the switch itself or with the wiring that connects it to the rest of the amp.
To troubleshoot these issues, you may want to try the following steps:

1. Make sure that all the cables and connections to your amp are secure and not damaged in any way. Loose or damaged cables can cause all sorts of problems, including noise and intermittent operation.
2. Check the fuse in your amp to make sure it's not blown. A blown fuse can cause the amp to make noise or to stop functioning entirely.
3. If the problem persists, you may want to consider taking your amp to a professional technician for repair. A trained technician will be able to diagnose and fix any hardware issues that may be causing the problems you're experiencing.

I hope this helps! Let me know if you have any other questions.

There could be several reasons why your Behringer Powerplay unit has switched off and is not powering on again. Here are a few troubleshooting steps you can try:

1. Check the power source: Make sure the power source you are using is working properly. Check that the outlet is receiving power and that the cable you are using is not damaged.
2. Check the power switch: Make sure that the power switch is turned on and that the unit is receiving power. If the switch is on and the unit is not receiving power, it could be a problem with the switch or internal wiring.
3. Check the fuse: Check if there is a fuse in the Behringer Powerplay unit and if it has blown. If the fuse has blown, replace it with a new one.
4. Check for other issues: There may be other issues with the unit such as a faulty power supply, overheating or a component failure. In this case, it is best to take the unit to a qualified technician for repair.

If none of these troubleshooting steps work, you may need to contact Behringer customer support for further assistance.

I am guessing it is solid state? If it were tubes it would be an easy fix but the solid state amps are very hard to diagnose and repair. I think the Guitar Center has a repair department and they probably know the trouble shooting steps. I am guessing it is a board, but the way to trouble shoot would be to know how much current should be flowing to individual leads. I do not have this information, but you will need a multi meeter in order to start the process. No reputable repair shop should charge you any thing to give you an estimate.

If the third prong is the round one, then that is the ground to your amp. It will still work, however, the amplifier will not be properly grounded. So in a pinch you can use it, but you need to get the cable replaced. The ground wire is there for your safety, in case you plug your amp into a mis-wired outlet or if you are plugging in another instrument like a keyboard, mixer etc. that may be mis-wired. This could lead to a bad shock or worse. You have been warned.

Either your key scanning section or the power amplifier has fried.
Try playing the demo song, if the sound can be heard then the scanning section is faulty. You may download the servicemanual from Elektrotanya com and repair the keyboard.

Old reply so hopefully it's fixed. Dust or hair can get through the gaps and land on or near the contacts of the electronic key sensors. To be on the safe side (rather than doing a diy) take it in to the technicians. They'll have it fixed in a jiffy

have a look here:
http://www.ehow.com/how_8698510_fix-roland-cube.html

although it doesn't mention the fuse you will probably find it. Sometimes there is a fuse access on the outer case.

Do some tests: Plug a set of headphones into the line outs and tell us which ones if any have sound. Note that only one side of the headphones may have sound and it may be low volume. We need to know if anything is coming fromt he preamp. Makesure the output switch is set to one of the speaker on positions and not just phones.

Hello,

if it does not power up, then it means its having a power problem. it might have worked fine in the past, but that's electronics for you. Power surge, irregular power supply, excess power supply, etc can affect the unit thereby not making it to power on.

This unit must have a power supply board in it where power enters from the mains. A capacitor, fuse, diode, etc may have been defective on the power board and maybe that's why its not making the unit turn on. There might also be some disconnection or something, inside the unit which is not making it to power on.

To actually find out what's wrong, you need to disassemble the unit with a screw driver and check what's wrong. You will be needing a meter in order to test the components on the power board, once you detect any bad component, you can make necessary replacement at any electronics accessories store withing our vicinity. This is the only way by which you can detect the problem.

Of course, testing the power board with a meter will require someone that has the ability. So it you can't, then you might be needing the help of a repairman or you can call a friend that has the ability to help you out.

I wish you the best of luck.

Take care........

Not good. If you have electronics experience, you can replace the power amp IC to fix it.
Paul