Occasionally at power up, all the channel signal indicators will flash simultaneously on and off, staying lit for random lengths of time, there will be slightly more noise coming from the main outputs of the board when the lights are lit and the condition usually will stop after an hour or two if it starts. the problem can occur with no input connections to the board and seems to not be affected by any thing connected to the board when there is stuff plugged into it. Thanks and have a great day. Mark.

The flashing green light on your Behringer Pmp500 mixer desk indicates that it's receiving a signal, but it's unclear why the first 4 channels aren't working. Make sure that all cables and connections are properly secured and that the power supply is adequate for the mixer's needs. If the issue persists, you may need to consult a professional for further troubleshooting or repair.

If sure that power is reaching and getting into unit, then confirm that a signal is also reaching unit. If both are positive, then your gear is FUBAR if signal is going into correct input.

How is the iPod connected at the class?

The VIP channel will override the signal if a mic is connected.

Are you using the same cable for dance AND home?

Is the ipod getting interference at the class from a wi-fi signal?

See attachment. It might help. https://classrooms.at.ufl.edu/wp-content/uploads/portable-pa-system.pdf

Genuine and consistent random flashing is normally a cable fault if is the main VU graph but there are other symptoms as well. If is the O/l (Clip) or Solo Leds on a channel strip have you checked for earth loops etc? Does it do it all the time or only when there's a signal? Which Leds are flashing and is there anything else that is not behaving correctly? It would seem if you can get a repair shop to have a look this would be your best bet.

1. Make sure nothing is plugged in.
2. Turn the GAIN, LEVEL, and FX knobs for each channel, counter-clockwise all the way.
3. Bring the MAIN fader all the way down.

If the signal LED's above the MAIN fader are still lit, then the board most likely has a short in it and will require repair.

If the signal LED's are dark, repeat the following on each channel...

1. Rotate GAIN clockwise until the mark on the knob is at "12 oclock".
2. Rotate LEVEL clockwise until the mark on the knob is at "3 oclock"
3. Raise the MAIN fader to "0".
4. Check LED's - if they light up then the channel you are working on is "noisy" or has a short in it.
5. Return GAIN, LEVEL, and MAIN to "all off".
6. Repeat with next channel.

Make sure you are using BALANCED cables from this... eithe XLR or TRS cables. Using TS unbalnced cables MAY ground out the signal which is sent as balanced. Here is a schematic for the 24 channel unit... yours just has eight more channels. http://elektrotanya.com/behringer_ub2442fx-pro_sm.pdf/download.html
Scroll down to "get manual" and click to download. Ignore other download links.
By looking at the signal paths, you can OFTEN do a lot of testing from the available jacks. If the contacts on the right main INSERT jack go bad, that would cause your problem,,, NEVER use other than an insert cable in these jacks.

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.

There are LED's all over these and you don't say which are lit... If they are mute or solo LED check the switches for a solo button or mute that is set.

IF they are the output level LED's plug in a set of phones and crank the phone volume up to losten if there is feedback or oscillation that is causing this.

HUM PICKUP due to a ground loop could be causing this. Make sure that ANYTHING connected to the unit that is also powered receives pwer from the SAME receptacle. If you have devices that receive power from a different receptacle you MAY have a ground loop. Noise on power lines can DAMAGE the equipment due to excedding the common mode input and output capability of the unit.

Finally, a strong local radio transmitter MAY be interfering. Sometimes the interference can go backward into the output lines to trigger the indicators.

As a test, when event occurs again, start unplugging anything connected to the mixer and see if disconnecting anything stops the problem. If you can have the problem with ONLY the power connected, then check if you have inadvertently created a loop within the unit by your settings.

Please refer to the "signal flow" diagrams in your user manual to see the possible feedback paths you can cause a loop to form.

REMEMBER the oscillation MAY be occuring well above the frequency you can hear !!!!

If you have access to an oscilloscope that would see if there is an oscillation going on.

Disconnect the speaker wiring and speaker on the bad channel. Turn the level control(s) all the way counterclockwise and turn the amp on. If your DDT (limiting) light remains lit, it's time for a visit to your nearest certified Peavey service center....G.

Hello. The codes you seek are these: SYMPHONIC..... 520 904 906
AND here are the instructions:
Direct Philips Magnavox Universal Remote Code Entry PM335
1. Press and hold the Code Search button until the red
indicator stays on. Release the Code Search button.
2. Press and release the desired mode button (TV,
DVD, etc.).
The red indicator blinks, then stays lit.
3. Enter the 3 digit code from the code tables. Note:
after a valid code entry, the red indicator turns off.
For an invalid code, the red indicator flashes.
4. With your device on, press CHANNEL Up. If the
device responds, no further programming is
required. Note: If some buttons do not operate your
equipment, try one of the other codes for your
brand.