I have 3 of them. They're wonderful, when they work. One has major static. One won't hold the custom tunings. One has no sound at all. It was the only one that worked, then I adjusted the height of the saddle & bam....nothin'.

Electronic organs typically do not require tuning
A pipe organ produces sound via hundreds or thousands of organ pipes, each of which produces a single pitch and timbre. The goal of tuning a pipe organ is to adjust the pitch of each pipe so that they all sound in tune with each other.

Before turning the unit on, press the calib/batt button to check the battery condition.
The Fender AG6 only responds when the strings pitch is within a certain frequency range. If the guitars tuning is not within that range or if your installing new strings, first connect the guitar to the AG6 with a cord that you know to be in good working condition and turn the AG6 on. Then starting with the low E string (the thickest one), loosen the tuning peg to a point well below the standard tuning for that string. Then slowly tighten the peg as you strike the string repeatedly. When the strings frequency, comes within range you will see the 6E light glow and the needle will begin to deflect. When the needle reaches zero it is in tune. Do the remainder of the strings the same way then go back and recheck each a second time. If you have a tuning fork, you can use it to tune by ear then re-tune and maintain it with the AG6
Remember to always stretch then re-tune new strings several times.
If the AG6 does not respond even after checking the condition of the battery and the cord that connects the guitar to the tuner, the problem could be inside the AG6 with a bad connection on the board. Try moving the cord as you strike a string that you know is close to being in tune. Again a tuning fork would be helpful.
~DrewWatk

it is harmonic,you can fixed it by tuning.

Get it a repare at guitar center they have a pack of guitar strings for 5-10 Dollers they are located in Oregon Washington cailfoina if you relly want a cheep guitar that sounds good get bc rich or finder or eipcphone your guitar strings are probley getting old you have to buy a certain brad of stings that well last a year and if you need tuneing you can download an app for online tuning or you can type in online guitar tuneing I hoped this helped give me a message if you need more

by now I hope you've bought or made a new peg. with any tension on it, the splintered wood, broken at an angle, won't hold long enough to tune the string. either make one out of a dowel rod, with the tapered end sanded to fit tightly, or use a brand new one made of plastic.

The first thing to remember is that the strings will stretch so i always over tune it about a turn for small strings and 3 for the big strings. To prevent it from slipping when you are tightening the string pull it tight while turning it and make sure the string has overlapped its self a couple times before releasing it.

After waiting for a reply from Shadow electronics for over 2 months, I tracked down a source for information on how to wire a Shadow SH661 twinbucker. Robert from guitarelectronics.com replied within one day with some info (He worked for Shadow electronics until 1999). He said that the green wire is + (hot) and the yellow wire is - (ground) and the two other wires are wired together for full humbucking mode. If you want to wire them with a series/parallel switch go to www.guitarelectronics for more info on how to wire it. Shadow electronics customer support absolutely sucks ! With every other single major pickup manufacturer providing easy access to all of their pickup models wiring diagrams, Shadow doesn't and it's inexcusable. I won't ever be buying another one of their products for this reason and won't recommend them to anyone either !

Do you have the CORRECT power supply??? This takes a 9 VAC (not DC) adapter of 750ma current rating. People seem to try using "universal" adpaters to drive these devices that REQUIRE an AC power input and then they wonder why they won't work. So check that you have the official Behringer adapter for your unit. Note that AC adpaters are hard to find.

Sounds like a problem with the channel itself, if the clean channel works then its not the lead, input, guitar or the drivers. You have to be careful when opening up amps as some can hold a residual charge and there can be danger of electrocution.

I would recommend getting it looked at by a pro, it doesn't sound like an expensive fix.

Chances are there is nothing wrong with the mixer. IF you accidentally turned on Phantom power, that would cause the problem. Phantom is ONLY used with condenser mics and a few DI boxes. Turning it on can create noise unless balanced lines are used everywhere.