I have a Eurodesk 150 watt power supply that will not power up. It may have been struck by lightning. I am looking for a schematic and advice. Thanks, Tommy

Hi Bryant...
That particular power supply is hard to come across. There is a brand new one for your mixer on E-bay for $200.00 here:
http://www.ebay.com/itm/Behringer-Eurodesk-150-Watt-Power-Supply-For-Mixers-MX2442A-MX3282A-NEW-/252274097139
Hope this has helped you.

Check out elektrotanya.com you can get 2 circuits per day or pass the electronics test for more. Good Luck!

You need the correct rackmount psu, rated at 150 watts, I think it uses more than one rail volts so you can't use any old supply.

Behringer will not release schematics unless you are an authorized service agent... however, sometimes you can make do with the few schematics floating around... What is the problem with the unit? They typically use a switching power supply and the schematics of those aree usually similar enough to repair them.

Behringer re-uses a lot of design... you might look at page 2 of this download:

http://elektrotanya.com/behringer_pmh100.pdf/download.html

Scroll down to "Get Manual" and click to download. On page 2 is the SPS400 power supply which is one of the smaller switching supplies they use. You may find the schematic is close, possibly they de-populate it as a smaller supply. When repaired, start the supply for testing with a 60 watt light bulb in series with the power input. Use an isolation transformer for troubleshooting for safety.

You start by downloading the schematic here:

http://elektrotanya.com/peavey_valveking_100_212.pdf/download.html

Scroll down to the link "Get Manual" and download the schematic. Note that it has several pages of parts list preceeding the schematic.

Next, put a 150 Watt incandescent bulb in series with the power cord to act as a current limiting fuse. Now replace the fuse and proceed with testing. You may find that one or more filter caps have shorted. Also pay particular attention the the BIAS power supply. You should see about -35 to -40 volts. Note that the series lamp will come on if excess current is being drawn and voltages will be low if the lamp lights. If the BIAS supply has failed, it is possible your power tubes have been damaged.

Sounds like a power supply failure: This will be close to the service manual for your unit:

http://elektrotanya.com/behringer_ub2442fx-pro_sm.pdf/download.html

Check teh power supply output voltages. If no voltage the main switcher has failed. One needs to be adept at electronic repair to repair this and have proper tools and equipment. The switcher runs directely off the input power and work on that portion requires using an isolation transformer for personal safety.

Most of the problems with the small guitar amps are blown power amp chips. They usually use chips like the TDA2030 which look like a power transistor.
Most other problems involve broken connectors, bad solder joints or cracked circuit boards. The power supply area is so simple one doesn't need a schematic for that part which is usually just three terminal regulators for +/-15 volts. Schematics are often hard to find.
Try this site, although this is a different model, much of the schematic will likely be the same.

http://elektrotanya.com/marshall_valvestate10_10w_8001_8010.pdf/download.html

The power supply is blown. Argentina is 220V I believe. I have never seen a power supply schematic for this however being that it is low power it is a linear supply not switching. Either the rectifier diodes are blown out or possibly the output capacitors are blow due to approx double voltage. If you try this yourself be careful otherwise get a new amp. Good Luck