Occasionally, switching from red channel to green channel the amp gets stuck between channels both lights are off, and only a slight sound

To achieve a tone similar to Synyster Gates' A7X sound, you may want to start with the following settings:
Green channel:

• Bass: 5-7
• Mid: 2-4
• Treble: 5-7
• Presence: 5-7
• Gain: 7-8

Red channel:

• Bass: 3-5
• Mid: 3-5
• Treble: 5-7
• Presence: 5-7
• Gain: 8-10

When using the Boss MT-2 pedal, set the tone control to around 12 o'clock and the level to taste. This should give you a good starting point for a heavy metal tone.
It's important to note that these settings are just a starting point, and you may need to tweak them to suit your own personal taste, playing style and the room you're playing in.
Keep in mind that the MX112 cab will also affect the sound,so you may need to play with the eq settings on the head and the pedal to achieve the sound you are looking for.
Also, keep in mind that the sound of the DSL15H head with the MX112 cab will be different than the sound that Synyster Gates gets with his rig. However, the settings above should help you achieve a similar overall tone.

Simplest is to use the LR button at the bottom of the channel strips you want to send to the main mix. Make sure you set the gain for each channel in use so that the clip light just occasionally blinked then back off a fraction.
If you want to use sub channels assign the strip to the appropriate one 1/2 or 3/4 and the assign the sub to the main mix and bring the subs up.

have you tried using a foot pedal? Are you sure it is switching (green light turns red, etc?). On the lead channel are you turning up the gain all the way and the volume down?

Sounds like the switch is malfunctioning. First thing to do is get a can of Contact Cleaner. Spray it in the small space between the knob and the white dots, then turn it all the way - back and forth several times. If we're lucky, that will fix it. Good Luck

Back switches cleaning should do the job, if the two green lights show up at amp's front plate.

It appears from the manual that 00 is 100% full intensity just as you are observing... I can understand how you would be confused by the way it is written in the manual...

It also looks like you have to set chan 1 to be between 0 to 29 to select the RGB mode...and ALSO those color intensity values are "upside down", that is, 00 is full on for each color. and 255 is off.

These manuals can really be confusing.

There can be any number of reasons for this problem - solve it diagnostically by starting with something that you know is working and work through systematically to the other end.

1. Test a microphone on a separate amp to make sure it works okay. Check amp and speakers working. Check that all output cables from mixer to amp are working by testing separately.
2. Plug microphone into a channel on mixer. Also plug in headphones and turn headphone volume control up.
3. Make sure input sensitivity knob is turned up a bit (say half way) and main output faders (yellow) are up.
4. Check that channel is turned on (little button just above the channel fader- needs to be pressed down)
5. press pfl (pre-fade listen) button (next to button to switch channel on)- do you get any sound on main output or headphones or any indicator lights on mixer to show signal is getting that far (eitehr the individual channel metering lights or the main ones in the central section)?
6. turn off pfl - make sure channel fader (slider) is up - normal position is ) - about 3/4 of way up. Check lights again on individual channel and main output section - any signs?
7. Is the sub mix button for the channel pressed down - in which case you will need to bring sub mix (red) output faders up as well as main faders.
8. If you have got signs of signal on the individual channel but not main see if the channel has been routed somewhere odd (like a subgroup of channels).
9. Plug a working amp and speakers into one of the auxiliary outputs and use the relevant auxiliary send knob (on each channel just above the faders and pfl switches) to pan some signal to that auxiliary out - do you get anything? There is also a headphone socket for listening to the auxiliary channels (with a selector switch /knob to determine which one - make sure it is in the right position) try listening to the auxiliary output with headphones - anything? If yes the problem lies in the main output section.
10. Check that there is not a jack plug in the insert socket (to route signal through an external effects unit) without a matching return jack being plugged in - if appropriate is relevant effects unit switched on and correctly set up - if unsure remove the insert plug to take it out of the system.
11. Make sure any mute buttons are not switched in on main outputs.

You can download a full user manual here http://www.allen-heath.com/gl/gl2400

You've got a loose wire! What's happening is that there's a bad potentiometer (the electrical component behind the knob) that's out of place and is only connecting fully at one point in the knobs circuit (the part where you get full volume) take it in to an amp tech at your local music store and they'll fix it up easily.

I suspect you MAY have a severe ground loop. The green light indicates channel crossover if nothing plugged in.

MAKE SURE ALL connected equipment is powered from the SAME receptacle. If you service amps from receptacles at one end of the room and this board from the other end, you are ASKING for trouble.

Read up on "common mode" as it pertains to balanced lines. Equipment can be at risk if grounds "bounce" as they often do.

When green light with no inout shows up, slide all faders down first. Then unplug input lines one at a time... turn off the amps and then unplug the output lines one at a time. See if one of these inout or output lines was causing the green light.

You should be using BALANCED lines to your amps... either XLR or TRS types at both ends.

Your amp has two channels - "normal" and "drive." When you are on the normal channel, the "volume" knob controls your gain. In the "drive" channel, the drive knob controls your gain. In both channels, the "master" knob limits how loud the amp will get.

Most likely, you are on the drive channel, so the volume knob will have no effect. Try pushing the "channel select" switch. You should notice the channel indicator lamp (next to the drive knob) turn off. When it is off, you are in the normal mode. Yellow = drive, and red = "more drive."

Experiment with different settings to get a variety of tones.

To get the most out of this amp, try reading the manual, available online here:
http://www.fender.com/support/manuals/pdfs/manuals_elec/guitarpdf/Hot_Rod_Deluxe.pdf

Have fun - it's a great amp.