No sound, no tubes lighting up - did resistance checks

[Paul Birkeland]

Do you also get 6V AC at B7 and B8?  Is the key molded into the plastic base of your 6080 still attached? (Sometimes they break off)

[drewhaynes]

Yes I was getting 6VAC at B7 and B8 from the transformer... the key notch is still on my tube and I have tried 2 different 6080 tubes. Still no light in the tubes :/

[Paul Birkeland]

Yes I was getting 6VAC at B7 and B8 from the transformer... the key notch is still on my tube and I have tried 2 different 6080 tubes. Still no light in the tubes :/

B7 and B8 are pins 7 and 8 on the octal socket.  If you have 6V between those pins and you have a 6080 properly inserted into the socket, it will glow.

[drewhaynes]

B7 and B8 are pins 7 and 8 on the octal socket.  If you have 6V between those pins and you have a 6080 properly inserted into the socket, it will glow.

I'm back... long weekend, so hoping to try some more troubleshooting. I was reading 6V from somewhere on the *transformer* to B7 and to B8, but I believe I was showing 0V *between* B7 and B8. I will retest and post pictures of the readings, showing where I am testing.

EDIT: Also, I have not had my manual in a very long time. I can find the list of voltage checks on this forum, but are they *all* performed with one lead on ground, or are many of them measuring between specific combinations of terminals?

[Paul Birkeland]

To measure B7 and B8, set your meter to AC volts and put one probe on B8 and one on B7.

[drewhaynes]

Sorry, miscommunicating - I realized how to test between B7 and B8, I just meant for the general list of voltage checks on the crack, wasn't sure if they were testing from ground to each terminal.

Anyhow, I went ahead and retested between B7 and B8, as well as testing from where I *think* the transformer appears to be powering B8 and to B8 itself. I assume there should be a reading from this top terminal on the transformer to B8?

[drewhaynes]

Transformer to B8

[Paul Birkeland]

Is the Crack plugged in and powered up for those readings?

[drewhaynes]

Is the Crack plugged in and powered up for those readings?

Yes, I just confirmed by testing from the "power cord receptacle" (not sure the term) to the output of the power switch, getting ~120V. I also just tested from that same top, next to farther right, terminal on the transformer, to B7 and also to B8, checking for *resistance*. I got 0.2ohms from transformer to B8 and 0.5ohms from same transformer terminal to B7. Is that strange that both B7 and B8 would have low resistance to the same transformer terminal?

EDIT: Discovery! I could swear that I had read 6V from the very top RIGHT transfomer terminal to both B7 and to B8 at one point, but I could not replicate it. I was just performing that test again, and when the alligator clip pressed juuuust right on the transformer terminal, the 2 LEDs under the smaller (input?) tube lit up! I think the solder joint on that transformer terminal is crap - I'm going to resolder now. Hypothetically... could my entire issue be that terminal?

[Paul Birkeland]

That resistance isn't a problem.

Put one probe on terminal 4 of the power transformer and one probe on terminal 5, then check that AC voltage.

[drewhaynes]

That resistance isn't a problem.

Put one probe on terminal 4 of the power transformer and one probe on terminal 5, then check that AC voltage.

I got 120V on that test, but I just updated my above post. We may be on to something!

[Paul Birkeland]

It's tough to go back searching for edits, just post a new post, that's OK. 

The solder joints on the transformer aren't crap, we have received thousands of transformers from our winder and have never had a bad solder joint.

What I have seen here and there is that sometimes people get a little aggressive when they trim the wires connecting to power transformer terminals 4 and 5, and they can actually accidentally cut one of the wires leaving the transformer where it connects to the terminal.  (Again, the winder cuts those wires first, removes the enamel insulation, then wraps them around the terminal and applies solder; this is not a manufacturing issue)

If you've cut one of these wires by accident, I have always found this to be a repairable issue.  If you haven't cut one of these wires, but pushing on the terminals will change operation, then there's very likely a broken wire or poor solder joint that is responding to being moved by conducting properly.

-PB

[drewhaynes]

I'm now getting 5.6V from #4 to #5. I meant my *own* soldering on terminal 5 looked bad - I have now resoldered #5. I'm getting light in my 6080! I don't think there is any light in the smaller tube, or it's incredibly dim if so. It should light up also, right?

[drewhaynes]

Sorry for back to back posts, it doesn't like the file sizes in one post.

[drewhaynes]

Small tube