Trouble with iron upgrade installation

[Pfenning]

I have had my iron upgrade for years, and finally got around to installing it this weekend. The first amp went great and works fine. The second one seemed to go easier than the first, but I don't get any sound out of the amp. I rechecked all the connections, and everything looks solid. I can't find my original manual, I only have my c4s installation manual. I checked the voltages from the c4s manual and all looks good except the B6 which is 215 VDC instead of 155 VDC. Does anyone have a scan of the last page of the manual? I could use it to check out all the connection points and track down my issue. Anyone have an idea where I should look? Thanks.

Pfenning

 

[randy@matrixq.com]

Which model amp and which transformer upgrade are you referring to.  I'm guessing Paramour?

 

[Paul Joppa]

If it's Paramour, check the DC resistance of the transformer primary - IIRC, red and blue wires.

 

[Pfenning]

Yes it's Paramour, sorry. Paul, how do I check it? Measure the ohm reading across the red and blue wires?

 

[Grainger49]

Yes, unplug and test the wires.  As long as it is unplugged and you can get to the red and blue wires you are measuring the primary.

 

[Pfenning]

I flipped it over with the power disconnected and the tubes in. The DVM started out at about 23 mega ohms, slowly drifted down to about 19 mega ohms, then drifted back up to about 23 mega ohms before it stopped and now reads open. I took the meter off and on several times and can't get a reading now. It just shows open. Does that make any sense?

 

[Grainger49]

It should measure low ohms.  If you were not measuring through an open power switch it sounds like the primary winding opened.

 

[Pfenning]

I'm not sure what your reply means. I measured the ohms at tab 25 and 11 where the red and blue connect. Do I need to disconnect those wires from the circuit and check the ohms? Is the floating reading due to the capacitors hooked to tab 11 and 25?

Pfenning

 

[Grainger49]

No, if you measured at the transformer lugs it sounds like the transformer is open.  I'm not as familiar with the windings of this transformer as Paul Joppa.  So do tab 25 and tab 11 go to the incoming neutral and the power switch? 

 

[Paul Joppa]

Grainger, it's the output transformer - not the power transformer.

Pfenning, it sounds like the primary winding is open-circuited. Measure the channel that IS working to confirm that the right measurement is being made. You should see about 240 ohms.

 

[Grainger49]

See, smiley faces work for me.  Now that I'm on the same page...

One of the output transformer wires should be connected on the one side of the Parafeed cap and the other is most often at ground, choose one there are several.  There is another way to do it depending on the iron selected.  There is a good description on VoltSecond's site:

http://i244.photobucket.com/albums/gg7/Grainger49/SlapHead.gif

I can paraphrase his "Other Way To Parafeed" by saying that the wire that usually goes to ground ends up at the cathode instead.  Highly recommended if the iron is good for it.

I do have a Paramour manual.  I can scan, can't print it jams, but I can send either a .PDF or .JPG file to you.

PM your email, which I think I already have but just to be sure, PM.

 

[Pfenning]

I'll check it tonight. What do I do if it's an open circuit?

 

[Grainger49]

An open winding inside the transformer can not be fixed.  If it is at the winding attachments it can be fixed.

 

[Paul Joppa]

I'll check it tonight. What do I do if it's an open circuit?

Talk to Doc B. There are solutions, just a matter of deciding which one to support.

 

[Pfenning]

Ok, so I admit I have very little experience with electronics. Forgive me if I ask stupid questions or don't understand the first time. I checked the working amp with my ohm meter at 25 and 11, and the meter flip flops between open and 0 ohms. I'm putting the positive lead of my meter on the connection at terminal 11, and the negative lead of my meter at terminal 25. When I rechecked the non working amp, it did the same thing as yesterday. I showed an ohm load, drifted down, drifted back up and then went to open. When I recheck it, it shows open, no ohm reading at all. I verified my leads are plugged into the ohm port on my meter and I even installed new batteries in the meter. 

 

[Doc B]

Disconnect the red and blue wire from the circuit, in the amp that doesn't work. Connect your red test lead to the red wire and the black test lead to the blue wire. Set your ohmmeter to about 20K ohms and tell us the reading. You must have good contact between the test leads and the red and blue wires.

 

[Pfenning]

Doc, I did just like you asked and the reading was 2.3?? mega ohms. My meter is autoranging. I assume this means the OT is fine and I have another issue.

 

[braubeat]

If it was me, I would completely disconnect the transformer from the circuit and test it for resistance. Hook the test leads to bare wire.
That way you know fore sure you are not looking at bad solder joints.

Michael

 

[Pfenning]

Yes, I disconnected the red and blue wires. I did not disconnect the black and orange speaker tap wires. Will that make a difference?

 

[Grainger49]

It shouldn't make a difference if you are measuring DC ohms, no normal inexpensive hand held meter measures AC impedance.