Behringer xenyx x1204usb no power only light that lights up is +48v light know this is telling me something is wrong just dont know answer please someone help

SOURCE: Behringer XENYX 1622FX, won't power on. Phantom power works(?)

After reviewing the schematic, I don't understand how the Phantom power can REMAIN on with the power switch off... this CANNOT occur except for what energy is left in the 48 volt supply filter cap... This might last for minutes after the fuse went... UNLESS you have devices connected which are backfeeding the 48 volts. (which would be a disaster)

The 48 volts, +/- 12 volts and +/- 15 volts and the +5 volts ALL come from the SAME switching power supply. I suspect one of the filter caps went or the primary switching regulator a TDP245Y chip.

You should ONLY work on the line side of this using an ISOLATION transformer since the line side has lethal voltages.

To do testing, one replaces the fuse and puts a 60 Watt light bulb in series with the hot side of the inout line. The lamp "acts" as a resetable fuse and limits the current for testing. When all is well again, the lamp will remain out with the power flowing through it.

The D1 diode bridge and C7 input rectifier and filter are first things to check. You can do those with an ohmmeter.

I will caution you to ALWAYS power any and all equipment from the SAME power source. Plugging in devices from across the room will set up ground loops and any ground fault will fry equipment.

SOURCE: Behringer XENYX 2442FX Mixer. The power light

You have likely lost one, probably the +15 volt power supply... This is possibly a shorted component or a short on the circuit board causing this. It takes some skills at troubleshooting to find this. Sometimes using a thermal imaging camera will show hot spot... other times you have to search with a millivoltmeter. The rude solo light is driven by an op amp that uses both polarities of 15 volts and to turn it on it pulls negative... Hence I suspect the +15 is missing.

SOURCE: Behringer Xenyx 2222fx doesn't power

The Phantom power comes from a seperate winding on the switching power supply.Likely one or more of the other voltages are not present due to a failure of one or more components. The supplies are current limited so a short anyplace on the board may cause the problem. I had one of these short betwen the +/- 15 volt busses because somebody spilled liquid into it.

Here is a close schematic... a slightly different model with less channels, but circuoitry is the same, just more copies of it in yours: I believe it is zipped with four files... the last is the power supply.

http://elektrotanya.com/behringer_xenyx-1222fx_v1000_dpm5m_ub-spsu2_sch.zip/download.html