Left it on all morning...and it works!?

[sraevsky]

Some of you have seen in other threads where I've talked about my Allen ADC 2110, which wasn't playing at all. So I accidentally left it on all morning, and several hours later went back to turn it off. Just for kicks, I started playing something, and it actually plays! Have any of you heard of this or have any idea what the issue could be? Thanks.

[you795a]

It could be a loose connection. I would check the voltages and connections around the power supplies.

[sraevsky]

Good idea. Thank you!

[Philip Powell]

I have the same organ and the same thing happened to me when I got it. I didn't really think much about it as I was just happy to hear that it worked. I can't really think what would make it work although I could think of things that would cause it to not work after leaving it on. Maybe the organ finally realized that it had been "woken up" and needed to work.;-)

[sraevsky]

I have the same organ and the same thing happened to me when I got it. I didn't really think much about it as I was just happy to hear that it worked. I can't really think what would make it work although I could think of things that would cause it to not work after leaving it on. Maybe the organ finally realized that it had been "woken up" and needed to work.;-)

That's pretty funny. Maybe I need to leave it on all the time. :)

[Philip Powell]

I did that too for 4/5 months. The presets wouldn't save when I turned the organ off so I kept it on! looking back on it, it wasn't one of my brightest ideas.

[jbird604]

Any number of things could get "cured" by getting good and warm. Makes me think that your organ needs nothing more than a 100% routine maintenance procedure, which I have preached about endlessly on this forum for the past 15 years. Every organ needs this kind of work as it ages, and Allens of the 70's, 80's and 90's seem to be prime candidates, as they all have numerous mini pots and other pots in the audio chain. And Allen used RCA plugs and jacks to carry the audio through the console, and those are another item prone to getting intermittent and needing cleaning and lubrication.

But another possibility comes to mind as well -- between 1985 and about 1999 Allen built many different models with a certain type of power supply in the computer cage that is almost certain to fail sooner or later. The MADC models all were built with this supply, as were the W-4 and W-5 models during the MDS era. Allen revised this power supply at least 2 or 3 times over the years, but only in the past few years did they decide to quit supplying a standard linear supply as replacement for the original. Now they send out an off-the-shelf switching supply with +5 and +/- 15 volt outputs. They include instructions and a kit of hardware and cables and such to adapt this switching supply to the old MADC or MDS cages.

So.... IF your trouble is related to a failing linear power supply in the cage, it will only get worse, and in time the organ won't ever come up, even if you leave it on all the time. But that MIGHT not be the trouble. It is always possible that you need nothing more than the plain old routine maintenance that we've been talking about for years here.

[sraevsky]

Thanks jbird. Any pointers on how to do that maintenance myself?

[jbird604]

The steps have been written up a number of times here, so I won't go into details again. But in brief your job is to disconnect everything that can be disconnected, whether it's RCA plugs/jacks, terminal strips, Molex or AMP connectors on boards. Pull anything that is socketed or removable anywhere within the system. While you have each connector apart, clean the mating surfaces with something, such as a toothbrush, that will remove any dust, corrosion, or other gunk off the metal parts. I also like to apply a TINY amount of some kind of lubricant or de-oxing agent. I'm an old-timer and have used Vaseline as a general agent because the petroleum components in it act to lift away contaminants and it leaves behind a super thin film that eases insertion and protects against oxidation in the future. Others prefer to use a commercial product for this purpose.

I also pull each socketed IC that I can get to, clean the legs, use canned air to blow out the socket, and reinsert with great care, so as not to bend any legs.

The final part of the job is exercising the pots wherever they may be. Your Allen 2110 has several sets of "BTMG" controls in the tone generator cage -- one set for each of the four divisional channels, and if you have the card reader, it has two more sets of four. Don't forget to exercise the amplifier gain pots too, as they get dirty and noisy with time.

Once this is all done, you need to listen carefully to make sure you have the tone generator and amp pots back in proper order so the stops are balanced. I recommend a complete voicing process at this point, but that's another job for another day. And it has been widely discussed on the forum too.

Perhaps Michael (myorgan) or someone else will provide links to the various threads where these issues have been discussed at length.

[Philip Powell]

I have multiple topics about fixing my 2100's problems. Maybe you can find some answers in there.

[sraevsky]

I appreciate the overview.

[sraevsky]

Good news -- I reset two of the power amps in the back, and now it is working normally again. Thanks everyone.

[davidecasteel]

My first guess was that some electrolytic capacitors needed reforming.

David

[toodles]

I concur with Davidcasteel--electrolytic capacitors can sometimes deform if left unused for quite a while; applying power will sometimes reform them. I have a set of strobe lights, and if left unused for a bit, the manufacturer suggested turning the power supply on then off quickly, waiting about 10 seconds, then turning on and leaving on for several minutes.