My amp will turn on and even when I have the guitar and amp connected no sound comes from the amp. I don't know what to try to fix it, so I have left it alone, testing it every once in a while (it actually worked last night). I have a used MG15DFX that I don't think has been used much. Any help would be appreciated! Thanks.

maybe try turning the wire from your guitar to the amp around you might have the inlet in the outlet socket?
if not its probably damaged internal wires for the speakers

Download the manual

your gonna prob have to replace knob but try and re sodder the connections. if that doesn't fix it then its your knob that needs to be replaced

Hi J Wade. I'm Dave P. I'm not a guitar amp expert or technician but I've been using amps and effects for 35 years and there are a couple things I can suggest.

That kind of periodic noise/switch noise can be a symptom of having the polarity of the amp reversed. If your amp has a 3-position OFF/ground switch, try reversing the ground. If it doesn't, take the plug and turn it around. Just don't get near a microphone unless you're sure your amp is grounded the same as the P.A. It could fry your lips off.

Dirty switches to that too. You said the noise is in time with the delay's tap time which is set by a foot switch. If tapping that switch the first time generates a pop, the delay may have catch it and is repeating it. Turn off the amp, remove the delay foot switch and turn it back on. Still noisy? If not, give the foot switch a good cleaning.

When you turn the EFFECTS knob up, is it scratchy? Might need the potentiometer cleaned. What happens when you specifically turn the DELAY level down all the way while using the other effects? Noise still there?

That's all I've got. Hopefully, it was helpful. Don't wrack your brain over this too much. There could very well be an internal problem with your amp that will require a trip to the shop. You don't want to open it up yourself. Rock on but be safe.

Dave P.

Have you checked a different cable?. Also, when you plug in the unit, there should be a "pop" if everything is turned on. If there isn't, the connection is bad someplace.

If you are sure that the input device (I'm assuming electro-acoustic guitar) is working properly then it sounds like a clear case for return to the vendor! If it is brand new then don't even try to repair it. The phase buttons on the guitar channel are to help reduce feedback by putting the body of the guitar out of phase with the speakers. The speakers should all be in phase with each other though.

Do you turn on standby every time and wait for the tubes to heat up first? If you don't, it can severely damage the tubes.
But a common cause of this could be just old tubes. Like any other piece of technology, tubes get old. If you like to play your amp LOUD then they wear out a lot quicker. You have to replace tubes every now and then. Because I'm not there to check out your amp, I can't give you an exact answer but it sounds like that's the problem. This isn't always a bad thing. You can make the sound of your amp exponentially better with nicer, new tubes. Your amp has 12AX7 tubes. Very common tubes to use actually. I'm not sure what kind of music you play, I'm assuming mostly rock and blues. But here is a list of tubes and reviews on them.
http://thetubestore.com/12ax7review.html
This is how to replace a tube:
http://www.ehow.com/video_4438285_change-pre_amp-tubes-guitar-amps.html
Upkeep on a tube amp:
http://www.ehow.com/video_4438295_replace-tubes-guitar-amp.html
A note he doesn't make in the video is to dust out your amp. I use the compressed dust spray for the inside of computers.
So overall, stop turning up your amp to 11, make sure it's well ventilated and dust it out from time to time. Hope this helped.

It sounds like somehow the pre-gain is very high while the volume or post-gain is very low. Try turning the volume high on the effects unit and the gain low, and don't have the amp volume too low either.

Hello,I am a guitar tech in Nanaimo,BC,Canada and have run into this problem before.Simply replace the Takamine output jack [where the guitar cord goes into] 3 screws and solder,and it will work fine again.The jack has a switching mechanism in it and when it fails it shorts the output out.The jack is available at most Takamine dealers or Allparts http://www.allparts.com/SearchResults.asp?searching=Y&sort=7&search=jack&show=20&page=5

I would try hitting the side of the amp before turning it on. There may be a loose piece of solder or other conductive particle stuck somewhere. Bang the cabinet rather hard with your fist. If that doesn't help it might be a loose solder connection at a resistor or capacitor but a tech should check that out.