Not getting started even after connecting to power supply

Remember...it's a process of elimination when troubleshooting any thing. Have you tried another dynamic mic that does NOT need phantom power to operate? Connect your MP3 player to the Line In 1/4" connection and see if the sound passes to the output. Other than buying a replacement power supply, these units are not economical to repair...as I'm writing they sell for $70 new online.

If it buzzes when you have no inputs AND no output leads connected, there is a problem with the power supply... HOWEVER if you have used UNBALANCED output cables instead of the REQUIRED TRS BALANCED output cables, it is possible the noise is being driven backwards and that is what you are hearing. Note that at full gains, there often is a tiny bit of noise, usually hiss. Also make sure the supply is powered from the SAME receptacle as the equipment this drives such as an amp or powered speakers.

Start by unplugging anything attached to the amp to eliminate simple things such as a broken shield on an input cable.
If you still have the pronounced hum with nothing connected, then the amp's power supply may have a failed filter capacitor or diode bridge. Either of those would have to be sought by a tech with the right gear.

Usually it's the electrolytic caps that go in those, they basically "cook" and dry out, a power spike just pushes them over the edge. I've also had this problem with mine & 2 12 volt switchers for my HD and for the satellite had the same fix. I added a fan which helps. Another solution is to go to a second hand store, find 3 power suplies (15v,15v, 5V) and put them in place of the existing one. I am considering that myself as the firewire packed it in again last month and I had to jump over to the other 5v regulator to get it going again, even tho it was only 0.2 v short! Cheers, Sandrine

Hi, Provided there is a tag on the back showing the units model number, on that same tag should be the power requirements for it-buying a universal power supply, or even a used working one to another piece of equipment is acceptable as long as the polarity is the same. Polarity is located right next to where the power supply plugs into the unit. It will be a " circle with a dash inside it with a line connecting to a C looking symbol with a line coming out of it connecting another circle with a plus sign inside. " that is a typical outer ground/inner positive marking. a power supply will be marked the same. If they match the polarities are the same. Next make sure the power supply says the proper DC voltage and Milliamps or amps-Ma/A example: 2400Ma, 2.4a. I hope this helps and thank you for asking FixYa, good luck and don't forget to write back and let me know how I did, Prodzilla.

This is likely a very simple problem. Look for a connector that you did not seat properly or got pulled off when you opened the unit. The cables are often short and pull off the connections or even break a wire. It is NOT likely you need a new power supply.

ALSO see if you might have pinched a wire when re-assembling the unit.

Chances are you're hearing "60-Hertz" hum that comes from poor filtering in the organ power supply. Electronic circuits need direct current (DC) but our power lines supply alternating current (AC). The power supply converts the AC to the various DC voltages needed. Parts called filter capacitors smooth out the voltage, and if they go bad or lose contact because of bad connections the result can be the hum you're hearing.

There are other possible causes, but the filtering is so common it's a good place to start. You don't give the age of this organ, but if it's one that has been around a while, it's a good bet some of those capacitors are worn out.

If you can post a follow-up with a make and model, I'll check some of the technician groups and see if anybody has service information.

Good luck and thanks for using Fixya!

Those are a tough supply to fix. There are two power supplies on the board. A small switching one first starts and then when the input caps are charged a relay shorts out two large limiting resistors. Then the main power supply starts to generate the +/- used by the power amps.

When overcurrent is sensed, the supply shuts down... that is IF parts have not blown. Arcing within the power amp takes these out... the rear-most power amp arcs near the heatsink and wipes out parts there and sometimes in the power supply.

You cannot run this supply without a load on the small ofline switching supply that generates most of the smaller voltages. WARNING there are no bleeders on the capacitors on the big supply. If you don't bleed them and try to connect one of the power amps, you will get a NICE arc.

HINT: put a series light bulb like 100 Watts in series with the power input... saves fuses, the limiting resistors, transistors, etc.

Disconnect the audio line coaxes to the power amp and prop the face still connected to the supply to work on it.

The first thing is to weed out shorted transistors in the main supply (leave them out) and verify that the small supply is operating. If it is not, then likely the two sand coated limiting resistors have been blown... this is just a start on a typical repair of this.

Try the following sites

http://www.powerstream.com/power2.html

http://www.platinum-records.com/Numark-21V-750MA-AC-Adapter-Power-Supply-prod7509.htm

Or even a cheap replacement laptop power supply as these usually start at 1000 mA which will give you current to spare and have a longer lifetime. most of these cover from 15V to 24V and are either auto switching or manual select for the voltage. Plus you can pick these up from most electronic / big box / supermarket shelves

If you feel comfortable doing it you could try removing the back and examining the power supply. Make sure the power cord is not plugged in. Remove the screws holding the back on the organ. Look to see where the power supply is. It will be a fair sized metal box that the power cord comes out of. Look for a fuse holder on the box.If there isn't one or you already checked the fuse look to see how the power supply is fastened down. If you can remove it you can check the power cord from the plug end to the connection in the power supply with a volt ohm meter on the lower resistance scale. Check both sides of the power cord . Look for an internal fuse soldered into the circuit if there is one. Check it also. You can also check the power switch the same way. Think of the power cord and switch etc as a garden hose. You want to make sure that the flow of electricity is not interrupted any where between the plug and the power transformer. Do all these tests with the cord unplugged. Also avoid touching anything connected to the filter capacitors as they store dangerous amounts of electricity. If none of this helps note the plug that connects the power supply to the organ. Unplug it and take the power supply in to be tested. A good piano service place should be able to direct you to someone. Also remember that something had to make the power supply fail if it is indeed faulty. None of this is simple or recommended for a person who has no experience with electricity or electronic repair. If you feel at all hesitant about doing it you are better advised to consult a repair person. If you do have experience but no schematic you can still usually find the problem with careful thought and procedure. Break the circuit down into modules and test them one at a time starting with the power supply. It could be something as simple as a frayed cord or blown fuse to something as complex as a burned out transistor or faulty tube ( in the case of older organs) causing the power supply to fail. I once repaired a home organ that the power supply blew in again because of the customers house wiring. That particular wall plug in had been wired improperly. Hope all this helps.