Berhinger Xenyx 1622fx won't power up - just a feint flashing of the blue power LED

Can't it be repaired?

First read the instructions they contain some amazing information. I can not help you because I have no idea of what you want to know.

First read the instructions they contain some amazing information. The setup is a subjective function and dependent on what equipment you are connecting to it.

Here is your schematic:

http://elektrotanya.com/behringer_xenyx_1622fx.pdf/download.html

Scroll down and find link "Get manual" and click to download.. IGNORE other download links they are for third party viewers. Power supply is on page 11. This is a switching power supply running from line voltage. For personal safety USE AN ISOLATION transformer when working on it. First thing is to measure all the voltage outputs before and during shutdown. Switching power supplies often require use of an oscilloscope to repair. The three terminal regulators that follow the main switching supply each have thermal shutdown so if one of them is being overloaded it will shutdown and that voltage will drop way down. Use great caution when working on the supply!!!

You need to send your signal from the mixer to an amplifier and then go from the amp to your speakers.

Alternatively, buy a pair of active speakers.

If the blue power light does not light up then there is a problem with the unit or power supply. As it is less than a year from purchase I would advise returning it to the shop.

Here:
http://www.behringer.com/assets/1622FX_P0557_M_EN.pdf

The 2442 is just an extended version of the 1622FX. The manual covers the whole series.

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.

Use four (4) TRS cables. Connect from the
AUX "send" (left and right) to the input of the effects unit with two of the cables. Use the other two cables to connect from teh effects out jacks to the AUX "returns" left and right.

Suspect a broken circuit trace or broken solder. If they use a 7805 three terminal regulator, check the solder around those pins...
Berhinger does NOT release schematics except to their service facilities... I know... I have tried... I repaair a lot of their stuff and have to trace out the circuits.

Power supply circuits are rather easy except for the switching regulators if they have failed totally.

If only the +5 is dead, you should be only a filter cap and a diode or two away from the problem... Transformer leads and electrolytic leads with their weight are favorite to pull out of solder... On Behringer, often the traces are narrow and can have a crack in them.