Behringer Xenyx 2222fx doesn't power up. I've replaced the fuse and power cord, still nothing. When you flip the phantom power switch, the red +48V indicator light comes on on the front. Other than that, nothing. Any expertise you have on this board would be greatly appreciated.

You are unikely to find these as Behringer are very protective and anyway it is VERY unlikely you'd be able to make a cost effective fix even if you did get one.

More than likely, something has happened to the internal pathways to make it become unstable.

Have you tried unplugging EVERYTHING from the board? If not, try that, and just watch what it does with nothing but the power cord connected to it.

If unit still click off/on, then it probably needs service. I'm not so sure this is worth tackling yourself, unless you're willing to risk losing it altogether. Might be fun just to see what happens though. Good luck.

its the mute switch or the rheostat(slide)

I suspect that there is a problem on the effects board. Most of the signals go through this board. I would check the seating of connectors associated with the board.

Here is a schematic close to your unit:

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

Scroll down to "get manual" and click to download. Ignore other download links.

The phantom power is a separate rectifier and regulator. See page 11 of the download service manual for the power supply. Be careful when working on line operated switching supplies. I suspect you will find one of the other supplies is dead. If the phantom is OK, then the switcher is working and one of the rectifier/filter/regulators is bad. Check if an electrolytic cap is shorted.

Why did you change the fuse? If it was blown, then power supply has failed. Here is your schematic. The power supply is on page 14.

http://elektrotanya.com/behringer_ub-2222fx-pro.pdf/download.html

Scroll down the page at the site to the "Get Manual" Click on that to download the schematic. When working on line operated supplies use an isolation transformer for personal safety. The regulator chip IC2 has probably failed but test before changing. HINT: When restoring the supply, put a 60 watt light bulb in series with the hot power lead to act as a resetable fuse... saves fuses and also other components if all the bad parts haven't been weeded out.

This is likely a pwer supply problem... BUT do check that the power cord is properly seated... pretty common that these work loose.

The phantom power light wouldn't illuminate unless the unit was powered on. Possibly the main power indicator light is burned out.

You should find +/-15 volts and +5 volts as well as the phantom power... but that light can come on at much lower than desired voltage.

Note that the regulators are current limited so a short on the mixer board can kill one of the voltages.... but you are not getting any input from teh switching portion of the regulator so the switching part of the supply is apparently dead. To replace the supply you would have to call Behringer at 1-425-672-0816 to get the part number and an incident number and then call FullCompass which is their part distributor now.

When working on a switching power supply, use an isolation transformer for safety and use a 60 watt lamp in series with the power cord to limit current during testing.

The circuitry will be SIMILAR to the power supply found on page 9 of schematic you can download at:

http://elektrotanya.com/behringer_ub1204fx_pro.pdf/download.html

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.