ADC 5300 power issue

[Hamman]

Well I just finished hooking up my 5300 for the first time in alittle over a year.....since we moved to NorCal. Well I turned the organ on and immediately thunder contineously! I shut it off......turned the amps down to 3 and turned it back on....boom, boom, boom crackle.....stops going in and out....then quiet.....it plays....alittle more thunder then all is well for an hour. Turned it off for the evening came back this evening boom, boom power light flickers then goes out....the stops stop moving in and out......no sound......however repeating the powrr up does turn the amps on.....just dead every where else. The cage power supply has already been replaced a year ago. The breaker on the big power supply wasn't tripped but I cycled it anyways. The 2 smaller caged power supplies on the right hand console floor...their fuses are good. Any suggestions??

[jbird604]

Stop knobs literally moving in and out? That's weird -- The Ghost and Mr. Chicken?

Whatever power supply provides power to the USCP board would be suspect, but that wouldn't really explain the thunderstorm noise.

You'll just have to use your meter and test all the power supply outputs one by one. Each supply should be putting out a voltage very close to what is specified on DC. But the real info may come when you switch to the AC measurement. Obviously, a DC power supply should not be putting out any AC, but when a DC supply goes erratic like that, it will show up on the meter as AC voltage. So measure each one and if you find one that reveals more than a few hundredths of a volt of AC, it is probably failing.

I don't think I've ever seen a 5300, so I don't know exactly what power supplies you have. But they should all be easy to identify, as power supplies in Allen organs are generally housed in metal cages. Don't fail to check the cage supply, even though it's new. That thunderstorm sound is exactly what we had in the MDS when the cage supply went bad.

[Hamman]

Thank You John for your reply! I'll see if I can get a pic of the 2 smaller PS's on the right side though I remember one saying 5 volts. The Cage PS I put in a year ago was a used tested out of a ADC 4300 from a tech. It solved my first issue over a year ago with a smoking situation and smell from the old cage PS. I haven't had an issue yet till now. Yes the drawknob stops are going in and out...as if somebody is pushing different presets. Last night though, I watched the power switch pilot light go out and then it was silence...except the amps do still turn on....only cause I can hear the delayed click after I try turning the power back on. Indianajo has rebuilt the first original cage PS for me and I still have that to install...which I'll try this evening. The stops going in and out as if somebody is randomly pushing preset buttons baffles me. Would that cage PS have any effect on that? or the pilot light?

[jbird604]

Maybe. Cage and multiplexer board exchange data, multiplexer board connects to capture and m any other systems. Cage supply could be your problem.

[Hamman]

Ok...replaced cage power supply again with known good working one....still dead....except for hearing the delay amp turn on. No pilot light nothing. Took capture PS out and checked breaker again and 2 amp fuse inside...all good as well as metered all the other PS fuses. Is the actual power switch on the front of the organ switching AC mains or a control voltage for a relay? Help😭

[Nutball]

Track down where voltage is and isn't checking for both AC & DC since your DC might have gone to pure AC for a weird reason. You might track down at what switch or relay or plug the power stops. Does the amp get power? The relay might, but that doesn't mean the amp itself does.

[Hamman]

Here are the pics of the power supplies on the floor of the organ. Everyone of them checks out good except the smaller black caged one on the far right.....no voltage measurement...fuse is good. Suppose to be 5 volts DC. The wires hooked up to the terminal strip of the cage power supply are numbered 1-7...or8 but don't know what voltages they should be....I think I have a schematic somewhere but its probably buried in one of many boxes.....
Is there any other voltages to check for on the bigger capture PS then the obvious 5 volt terminals? I don't know what all the "sp" terminals are for or "n" terminals

[jbird604]

For the time being, I'd just switch off the capture power supply. It is not the problem. All those N and SP terminals are used by the capture memory board to trigger different groups of tabs or knobs to move. But that supply is only responding to a corrupted signal it is getting from elsewhere in the organ. So shut it off with the circuit breaker mounted on the front of the unit and concentrate on getting the organ to boot up and play. The organ does not need that supply in order to play. It only serves to move the tabs or knobs when a piston is pressed.

The cage supply should be outputting a clean and powerful +5 volts. There should be a paper tag on the metal chassis or heatsink of the supply showing what each terminal produces. There should also be +15 volts and -15 volts, and a delayed +15 for the internal mutes in the cage. I don't know the color codes off hand. Did you take a pic of the cage supply before you removed it? If so, look at it and see how the wires are connected. They should fit back onto any Allen cage supply in the same order. (I think the 5 volt wire is orange, and I know the ground is black. Not sure about + and - 15 though.)

That little supply in the floor that seems to be dead has to work or else the organ is dead, as it is the power source for the USCM board. If you don't get 5 volts of clean DC (no more than a few hundredths of a volt AC ripple), it probably needs replacing. I have taken to buying small and compact switching power supplies from various on-line sources. You can get a solid 5 volt supply capable of putting out 5 amps or more (which is plenty) for maybe $20. The official replacement unit from Allen probably costs $200. Of course, a local tech might be able to revive the one you have, if you want to keep everything original.

You are in a tight spot. It's hard to troubleshoot from a distance, so I'm hard-pressed to advise you. I do always start by measuring all the power supplies. Any supply that doesn't produce its rated voltage with pure DC and no AC has to be investigated. It can be a problem with the power supply itself, or it can be caused by a short circuit in something that is connected to the supply. Hard to tell without testing the supply on a work bench with proper load resistors and meters.

You may have to bite the bullet and call in a local tech.

[Hamman]

Thanks John!
Yes that smaller black cage PS all the way over to the right is dead! Nothing at all on the terminals...like I said before all the other PS have the correct voltages....well like for a +12V I might be getting +12.46v or something like that. I am going to concentrate on the 5VDC PS and see whats going on with it....I need to first make sure it is getting AC mains to it.....I have one of those 5vdc PS very similar in my Conn Custom 905 that operated the built in chimes...big caps and all...could I sub that in?
Also here is a schematic of my PS3

That little supply in the floor that seems to be dead has to work or else the organ is dead, as it is the power source for the USCM board. If you don't get 5 volts of clean DC (no more than a few hundredths of a volt AC ripple), it probably needs replacing. I have taken to buying small and compact switching power supplies from various on-line sources. You can get a solid 5 volt supply capable of putting out 5 amps or more (which is plenty) for maybe $20. The official replacement unit from Allen probably costs $200. Of course, a local tech might be able to revive the one you have, if you want to keep everything original.

[jbird604]

You're on the right rack now. Since you know that the 5 volt supply in the corner is not working, you only need to find out why. It has a fuse, and the fuse might simply have blown for no good reason. Or if it's blown, it may indicate some other problem, but it won't hurt anything to try replacing it. Be sure to replace it with the exact same type, same amps, and be sure it's fast-blow or slow-blow, depending on what the label says. One schematic I see on the tech site shows a 3/4 amp slow-blow. Is yours the same?

If the 5 volt supply still doesn't work, it probably can be fixed since it's a very simple circuit. Nothing in there except a transformer, a bridge rectifier, a filter capacitor, and a regulator IC, plus a few small capacitors that are used for spike suppression, and a diode near the output that serves as a last-ditch cut-off device should some reverse-polarity voltage get through the other components.

Transformers almost never fail, but the other parts are definitely suspects. There may not be over $10 worth of parts in there (besides the transformer), and you can find them all on Mouser.com. It wouldn't hurt to just replace them all at once, provided you have the skills.

But seriously, dirt cheap switching power supplies are out there, ready to drop in and work. Here's one. You MUST be sure to verify that you are connecting the fanning strip to the correct terminals, as they might be reversed from the terminals on the old supply. Other than than, it's a cinch.

https://www.digikey.com/product-deta...066-ND/4386537

[Hamman]

Again, Thanks John....so it's getting more puzzling now....Took out 5vdc power supply and bench tested....works! Thought maybe it wasnt getting any AC mains on power output module in organ....with metal cage off...plugged it back into organ...
5vdc.....hooked up both wires to 5vdc output terminals.......nothing....
yet the fuse isn't blown.....cant figure this out except to just drop in another PS!X-(

[Admin]

Sounds like there could be a short in the 5 volt line that is causing the power supply to go into the protect mode and shut down it's output. With power supply in place, detach one on the wires going to it and see if the voltage returns to where it should be. You could also use an ohmmeter to measure the load on the supply by first disconnecting them from the supply. Obviously a measurement of zero ohms would not be good.

[Pipeorganbuilder]

With the power supply working without the load and working with the load, you have something pulling the output down. Most of these supplies have a 7805 regulator chip(looks like a three pin transistor) that has a internal crow-bar (overload shutdown) that will drop the output if it sees a serious overload. Now the fun of finding what board or component is dropping it out.

Michael

- - - Updated - - -

Sorry admin.--We were typing about the same time.

Michael

[Admin]

Sorry admin.--We were typing about the same time.

Michael

:->That's OK. Great minds think alike!

[AllenAnalog]

Having just hooked up the MIDI board in my ADC-5300 to the +5 volt supply I recall that there are multiple wires attached to the output terminals of that supply. It might be possible that one of them got pinched and is touching other wires somewhere when the instrument was moved. So isolating where all of the 5 volt lines go and inspecting them for physical damage might be a good check to make.

The other possibility is that some loose metal part got wedged somewhere causing a short. When my console was moved they tipped it up on edge at a significant angle. The power cord I had coiled up inside the console actually rubbed the adjustment pot for the card reader voltage and turned it way down. So a thorough inspection around all of the boards and connectors with a bright flashlight might be a worthwhile project.