B3 and 147 troubles

[PGR]

Hi guys I have been updating this beast and I got it all back together two days ago after installing a few AO -28-1 replacement parts and for a short time it did work ...I walked away from it to turn over the burgers and came back to a loud hum coming from the 147 and absolutely no sound ability from any of the keys or tabs on the hammond. I can effect the volume of the hum with the volume control on the leslie and also the load capacitor switch on the 147 (not sure where it should be positioned) and hopefully this means the leslie is not at fault. how can I be sure....anyone have a suggested test that will point specifically to the leslie or to the ao 28-1?

I can also tell you I measured the output at the red G terminal and got 59-60 hertz without having any keys pressed or tabs on or drawbars pulled at 1.5v RMS

Thanks for the help everyone

[Sweet Pete]

Try moving the load output selector to 8 ohms? Might be ungrounded on 'open'?

[PGR]

thank pete for the suggestion the 8ohm setting does make the leslie quieter - less hum. it does have two speeds but the organ is making no sound from any settings percussion or vibrato or b or a# presets or any other on the upper or lower. originall I thought the the volume knob on the leslie had an effect on how loud the hum is , it does not I did attempt to pick up the red G and push it through the speaker I have all I get is a rather large 60 cycle hum so now I suspect the AO-28-1 is broken!

[Sweet Pete]

If you just worked on the AO28 there's a good chance a solder joint that looks fine needs some attention.
On one I recapped,I reflowed the C14 leads with the result being less hum and noise.
The resistor that balances vib/dry also.....

[PGR]

Ok I will have a look over the joints the weird thing is that yesterday it worked after putting the AO28 back in -I have problems with messed up tones and missing notes but now it has suddenly regressed so I have nothing but 60cycle hum and no notes anywhere but on the red G I get the 60hz and an RMS reading of 1.5v which is being generated somewhere Maybe I will flip the AO28 tomorrow and see if I have burned something

[PGR]

Has any one taken the Ao 28 and without unsoldering all those wires just flipped it over to work on it?

[Drawbar Dave]

Yes I disconnected the swell arm and laid it on it’s back.

[PGR]

Hi Dave , Were you able to test it live?

[Drawbar Dave]

Hi Dave , Were you able to test it live?

I wasn’t testing, I was recapping so the power to the organ was disconnected.

[PGR]

I spent the day testing the B3 and I have some troubles There are three separate issues here on just tone generation. None of these issues are related to a TWG fault it is producing ..... albeit it could be tuned better or peaked if you will.


I have missing tones 53 55 63 on both manuals. I cross checked every drawbar and always the same result
I also have a tone missing on just the upper 79 So to find these I am refloating the solder and checking again the TWG to make sure it is producing. Then I will be chasing the wiring looking for a short or broken wire . I did verify the manuals continuity before but maybe broke some wires on installation.

In all the testing so far I have side stepped the AO 28 it has a dead short somewhere so after I get the manuals working right I can go after the AO28 short.

My biggest issue is tone 13 is gone but shows up in the third or fourth octave where tone 49 should be.....and tone 49 shows up where tone 13 needs to be. IT is weird . How can this happen?

I can also tell you that in all of this.......what happens on the upper is duplicated on the lower. Exactly except for tone 79 missing on the upper but plays fine on the lower.

Your suggestions would be welcome.

[enor]

My biggest issue is tone 13 is gone but shows up in the third or fourth octave where tone 49 should be.....and tone 49 shows up where tone 13 needs to be. IT is weird . How can this happen?

13 and 49 are close to each other on the generator terminal strip - the 3rd and 1st terminal counting from the start motor end. You've probably mixed them up when reinstalling the harness.

[PGR]

Enor this is the wiring harness at the right end closest to the starter motor . I think your suggesting I just switch these two to the other tang IS that correct?

I think I may have put them in this way because the furthest to the right is the longer wire. however the bundling wrap is on the wire to the left suggesting it should be on the right of all. These are of coarse from the harness along the top of the tabs

[enor]

[ATTACH=CONFIG]30779[/ATTACH][ATTACH=CONFIG]30780[/ATTACH]

Enor this is the wiring harness at the right end closest to the starter motor . I think your suggesting I just switch these two to the other tang IS that correct?

I think I may have put them in this way because the furthest to the right is the longer wire. however the bundling wrap is on the wire to the left suggesting it should be on the right of all. These are of coarse from the harness along the top of the tabs

Yes, those two are reversed.

[PGR]

Ok so I reversed the two and Got back 19 and 43 just were they are suppose to be Big Thanks to you now on to the others and re flow the 62 to get it back I think i need to lift the manuals and check the loop now for 53 and 55


update: Enor thanks for the suggestion on 19 and 43 I reversed them and they have shown up just where they need to be,

Now I have a question or two,

53 and 55 are missing on both the upper and lower manual .......I have cross checked the TWG and in both cases it is working. So this condition leads me to believe that the wire is broken between the TWG and the tag for the upper - the lower may still be intack but the signal is not getting through to the manuals. What else would cause this?


Also I have 79 missing on the upper only forget the (drawbar) but only on the upper. This suggests that the tag to the upper is disconnected Anything else?




Thanks guys Appreciate the assistance.

[PGR]

Any one got the answer to these questions.

53 and 55 are missing on both the upper and lower manual .......I have cross checked the TWG and in both cases it is working. So this condition leads me to believe that the wire is broken between the TWG and the tag for the upper - the lower may still be intack but the signal is not getting through to the manuals. What else would cause this?

Also I have 79 missing on the upper only forget the (drawbar) but only on the upper. This suggests that the tag to the upper is disconnected Anything else?