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M3 perucssion - no decay & reset.
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This could also be dendrites in the upper manual. If shifting the buss bars make the problem go away then you know where to look / clean. If it is the upper manual then you could add foldback while you have it apart for cleaning.
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Guest repliedHi there I have the same problem with my M3 (1959) I can`t see the letter very well on the chassis so witch one should i zap with the 9 volt dc the first wire from the percussion trim is green , brown , red,blue and two yellow thanks
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Re: M3 perucssion - no decay & reset.
Thanks again george, case closed!
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Re: M3 perucssion - no decay & reset.
Yep, output tubes 6650's. Also, a new filter cap.</p>
George
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Re: M3 perucssion - no decay & reset.
Thanks for all the help George, everything turned out well with the organ percussion and hookup...</p>
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Now the leslie's on the fritz (145)! It plays fine for a few mins, but soon the volume almost completely diminishes. You can still hear it the organ faintly, and if you adjust the volume control on the leslie amp, you can bring it almost up to 3 o'clock (volume 8?) and still barely hear anything. If you turn it the rest of the way up you hear it a bit louder, but with horrible intermittent signal/distortion. At this point I tried my own leslie which was fine...then after about 15min I plugged the main leslie back in and it played fine again...then died soon after. I wasn't around for the first time this sound decay occurred, but the people around compared it to an organ on its death bed...just a strange, distorted, dying organ tone. I've checked and i'm positive the leslie amp is problem. </p>
Are any of the amp's components suspect?
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Re: M3 perucssion - no decay & reset.
Oh, I see. I'm thinking console as that's what I work on every day. In consoles, the preamp is switched on and doesn't have mains AC going to it when off. The M-3 has mains going into it of course. Not having one here to look at, just measure AC power on the three terminals with it on and with it off. You will see how it's switched. Looks like you have it figured out already. You can clip a light bulb on the terminals you think are right and test it.</p>
Sorry for the confusion. (gotta stop thinking consoles all the time!!! Errr!)[:$]</p>
George
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Re: M3 perucssion - no decay & reset.
[quote user="geoelectro"]
Were you talking about the cover on the generator? I was talking about the cover on the amplifier. This is where kits are usually connected. The amplifier is switched of course. [;)]</p>
George
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[/quote]</p>
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I was also talking about the cover on the amp. There are 3 terminals. One is AC Neutral (GY), and connects to the amp transformer. The next is AC Hot (BL), which is connected to the Run switch, which is returned to the amp via BN, which connects to the other side of the transformer, powering up the amp. So there are 2 live terminals and one off, while the organ is off. According to that schematic GY and BN should be used, no? I'm using the tester just to be 100% sure...but I wanted to know if i'm reading the schematic right.
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Re: M3 perucssion - no decay & reset.
Were you talking about the cover on the generator? I was talking about the cover on the amplifier. This is where kits are usually connected. The amplifier is switched of course. [;)]</p>
George
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Re: M3 perucssion - no decay & reset.
[quote user="Model E & Me"]</p>
An ammeter has very low
impedance, since it is placed in series with the circuit. Since you had
your multimeter connected as an ammeter, what happened was that you put
a direct short circuit across the 120 volt power and the test lead
conductors burned off before the circuit breaker in your service panel
tripped. You were lucky - the outcome was better than it could have
been.[/quote]</p>
Thanks for explaining. I did notice the fuse was still good inside the meter...Glad I didn't didn't do harm to the service panel (or to myself)! A new page has been written in my book of common sense.
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[quote user="geoelectro"]</p>
Should be blue and gray. Hey! Be careful dude! [:O]
</p>
George
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[/quote]</p>
It looks like Blue and Gray are Un-switched, by the schematic I would guess that they are live even if the organ has not been turned on. Brown looks like it becomes live when the Run switch is activated. Or am I reading this wrong...</p>
And I'll be careful! (Think I always am...just got rushed yesterday, I suppose. Won't let that happen again.)</p>
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Re: M3 perucssion - no decay & reset.
[quote user="johnny b3"]
...I don't know what happened but I ended up blowing out my test probe leads a large blue zap and some sizzle and smoke. I thought at first the meter was fried (I realized the + meter lead was not plugged in the correct location - 10A instead of VOmA) however now i'm checking and the meter is fine, and neither test lead has continuity. </P>
[/quote]</P>
An ammeter has very low impedance, since it is placed in series with the circuit. Since you had your multimeter connected as an ammeter, what happened was that you put a direct short circuit across the 120 volt power and the test lead conductors burned off before the circuit breaker in your service panel tripped. You were lucky - the outcome was better than it could have been.</P>
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Re: M3 perucssion - no decay & reset.
Should be blue and gray. Hey! Be careful dude! [:O]
</p>
George
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Re: M3 perucssion - no decay & reset.
I went back today to hook up my cheapo 147 kit, when it came time to add the power section I took off the protective cover at the AC terminals on the M3, and proceeded to check to the switched/unswitched connection points with my multimeter. I don't know what happened but I ended up blowing out my test probe leads a large blue zap and some sizzle and smoke. I thought at first the meter was fried (I realized the + meter lead was not plugged in the correct location - 10A instead of VOmA) however now i'm checking and the meter is fine, and neither test lead has continuity. </p>
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Now, I dont know if this came before or after me flashing the percussion circuit. (I used one of the meter leads to flash it - the pointy end in the tube socket (Pin 1 CC) and the stubby end on the K terminal). There was no spark, but only a click through the speaker. The percussion seemed to work in the 2 mins I had to test the organ. </p>
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I need Brown and Grey for switched power, correct?</p>
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Re: M3 perucssion - no decay & reset.
Just do it! Heh...heh.</p>
I have serviced Hammonds for over 30 years. I will never intentionally give out incorrect or misleading info. I may accidentally do that though :o( </p>
I have flashed percussion and vibrato circuits for decades. The only failure this ever caused, was to blow out the rectifier tube because of a larger than typical short. That it why I don't advise people to get the High Voltage from the 6x4 circuit. By getting it from the 12AU7 percussion socket, you have enough isolation to prevent rectifier damage.</p>
Yes, the other terminals may be flashed too but I always do the K terminal and then check it. That usually fixes it.</p>
Dentrite is a metallic growth that forms on metal surfaces that have a lot of tin in it. You can go to NASA's site and actually see microscopic pictures of this problem. These growths occur inside the preamp, percussion switch box, vibrato switch box, vibrato scanner etc. Even in the manuals themselves. Flashing is a technique of applying a voltage that can "burn" away any shorts caused by the growth. Of course you could fully disassemble all these metal boxes etc. and clean them manually. In fact, that kind of repair would likely last longer. Many will disassemble the vibrato scanner for example and after cleaning, paint the metal surfaces to prevent this growth from returning. I have rebuilt many scanners but never painted one. I still have not had to rebuild any scanner that was already rebuilt.</p>
BTW. The new standard adopted by EU and coming soon to a technology product near you is the complete removable of lead from solder and parts. RoHS is the standard and you will find this label on products already. The idea is that when these products are throwned away, the lead "could" leach into the ground water and raise the lead levels. Sounds right, but studies have shown that lead in solid form does not do this. I would never advocate any practice that worsened our water supply but I am dubious of this idea. I believe it's a typical over reaction to a perceived problem. Guess what, NASA and other Governments are exempt! Why? Because they made the case that lead makes better products. As you know, solder is usually a mixture of lead and tin. Well, as we know, lead lowers the melting point of solder but it turns out that another benefit of lead is it reduces the metallic growth in the tin. Solder with no lead has no natural way to supress the growth meaning that products made with no lead content won't leach lead into the enviroment and also won't last very long.</p>
George
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Re: M3 perucssion - no decay & reset.
I found the HammondWiki article about flashing and I have a few new concerns - </p>
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First, the author(s) say this procedure may cause problems with other areas of the organ (even if done correctly), and Second, sometimes the procedure is carried out on other terminals (H, J, M, and N wires) AND sometimes the wires are to be disconnected at the terminals before flashing. Thoughts?
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The article mentions that this is a shorting problem - and I should check the resistance between K and ground to find a few hundred ohm reading (supposibly, if this is actually a dendrite problem), as well as normal operating voltage readings at this point. However this article was written with a console in mind - can I follow its instructions precisely? (i'm not sure about the discrepancies between the AO-28/29 in regards to this procedure).
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http://www.dairiki.org/HammondWiki/PercussionTroubleshooting</p>
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Re: M3 perucssion - no decay & reset.
Do the other percussion switches need to be in any certain position during this procedure?
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