Problems with power transformer in Fender blackface Vibro Champ

Hello,
I have a question about the Weber international power transformer (W022772INT) I bought for my old Blackface Vibro Champ.
Once hooked up I put on my amp, but there was no sound untill I saw some smoke coming out of my Vibro Champ. I opened up the amp and saw one of the green fillament wires had started to melt.
Now this is how I hooked up the PT, I'm in Belgium, which means 230V:
2 Red wires to 4 and 6 on the 5Y3GT tube
2 Yellow wires to 2 and 8 on the 5Y3GT tube
1 Black wire to the fuse
1 Gray wire to the on/off switch
1 Green/Yellow wire twisted together with 1 Red/Yellow wire to ground.
So far so good I guesse...

But then the 2 Green fillament wires come in. I hooked up 1 wire to the 6,3V pilot light and the other green wire to the ground of the 6,3V pilot light (eventhough there was only one green wire on the original power transformer).
And that's when it strated smoking and so the grounded green wire started to melt...

Now I unsoldered that wire, switched the amp back on and I have no sound at all. The amp turns on, pilot light lights up, but there is no sound...
What did I do wrong and what should I do?

Thanks a lot and all my best,
Bram 

you can either remove the grn/yel wire from ground,

or make the amp more quiet by getting rid of the common ground/heater set up,

they ground one end of the heater circuit to simplify wiring,


so when you put both the grn/yel to gnd and the grn wire to lamp ground, you created a dead short across one half of the 6.3 heater wires,

so you can remove the gnd on the 12ax7's and 6v6 and use the standard twisted grn wires to the tubes in conjunction with the ct to get a semi quiet amp.

you will need to lift the lamp ground, just use some plastic under the lamp holder, or whatever else you can figure out,

Thanks CJ, but the way I wired this Fender Champ is exactly the same as I did with my two Fender Princeton amps and I can tell you, those Princetons already work 5 years without any problem. I have no shorted grounds there... The difference is that a Princeton has two green wires that go to the floating heaters and that the Champs only has one. So what to do with the second green wire that comes out of the power transformer?

Can't I just remove the green wire that I grounded to the pilot lamp?
Or should I wire all heaters double like in a Princeton amp?

And one more question: shouldn't I have used the 600V wires instead of the 660V wires? What would be the difference?

Thanks again for your help!

you can snip and tape the grn/yel and simply ground the other grn wire,

but this is a very noisy amp to begin with (single ended) so grounding one end of the heater just makes it worse,

it is one of the few fenders that use a grounded heater,

Thanks again! I'll try that later this evening.

And about the high voltage wires: should I take the 660V or 600V (Weber PT's have the choice)?

600 will give you about 360 plate V, 660 about 400, which makes me nervous,

Ok, this is where I'm at:

I opened up the tranfo's end bell and re-insulated the melted green wire with new heat shrink. To me it looks fine now, but I can't see what's really inside the PT of course...

Now I wired the power transformer like this:

One green wire twisted together with the red/yellow wire, both soldered to ground
The other green wire to the pilot light's fillament
The green/yellow wire is loose now, cut off and secured with heat shrink

The rest of the wires stayed the same, although I now took the red/white 600V wires for a slighter lower voltage in order not to get nervous  ;D

CJ, can you confirm the new wiring is correct? Hope the PT still works... I'll wait for your response before I power up the Champ again.

Thanks!

I just checked on some continuity things and found out that the two poles of the pilot light are soldered together and thus giving continuity... (I measured this without the lamp). Isn't that strange? Because before I started working on this Vibro Champ everything worked (except for the fact that it wasn't grounded and made a lot of hum).
I checked another Champ I have and there the two poles are not soldered together.

Could de-soldering the two poles of the pilot light solve some problems?

In my post above you see how I now wired the PT. Correct you think?

Thanks!

your pwr transformer is wired correctly now,

how did that lamp get soldered together, are you sure?

your heater winding is very low ohms becasue the wire inside the transformer is very thick,

so if you measure from grn to grn, you will get almost a dead short, there should be maybe 0.3 ohms or something, but your test leads have about 0.2- 1 ohm,  so it is hard to get an accurate measurement, you would need what is called a "four wire" system in the voltmeter,

short your ohm meter leads together and write down the resistance value you get, this will be your offset that you will subtract from your readings from grn to grn,

measure from grn to grn again and subtract the offset, this will be your real reading of the heater winding resistance,

since the heater winding is wired to the pilot lamp, it can make it look like a dead short,

put the lamp in and plug in the amp for 1/2 second to see if the lamp lights,

you will not burn anything up in 1/2 second, so do not worry about frying the heater winding, the heater winding is big wire so you will not break this wire by turning on the amp for a split second,

I just took a photo of the pilot light and made a small drawing of the pilot light to make clear what and how it is soldered.

Any thoughts anybody? Is this standard, or why would someone ever have soldered these parts together in the past? I can clearly sea that the Vibro Champ, at one point has been servinced by someone...

And the drawing...

And what's more, I put the amp on for 1/2 second and the light worked...

What do you think? With the PT all wired up correctly, should I try and play the amp?

plug in and play,  looks ok,

you can find the old Fender chassis diagrams online,

or buy Aspen Pitman,s amp book or Gerald Weber's amp books,

Thanks CJ, you're right, I should get a good tube amp book. Are those two books you suggested the best options?

Just one more thing: I plugged in my Champ and played it. Everything seems to work, except that it makes quite some humming noise... More than before, if I remember well. Could it be that there is actually something wrong inside the power transformer that now causes the hum?

Thanks!

Desktop Reference of Hip Guitar Amps by Gerald Weber is the only book you need,

that power transformer wants that grn/yel wire grounded, but you would have to unsolder the pilot light ground, and run a pair of wires of of it to the heaters, you would break the grounds on pin 9 of the preamp tubes, and pin 7 of the 6V6GT, the 5y3 can be left alone,

the only other thing to try is reversing the grn wires, un-ground the grn and wire it to the lamp, then take the lamp wire and put it to gnd,

and try plugging the pwr cord the other way around, sometimes that can help,

I switched the green wires, as well as the power cord wires, but no difference. The hum stays there...

So you are sure it is something in the wiring that causes the humming? You sure it's not the PT that is damaged after I almost smoked it?
If you are sure it's just a matter of the PT wanting the green/yellow wire as a ground, then I still don't really get how I should wire the heathers. Would that be the same as the Princeton's floating heathers?
So snap the grounded sind of all heathers and wire a second green wire to all of them, leading to the pilot light? And would I need the second green wire from the PT then?

Still quite new to me, working on my Fender amps... eventhough I already built two PTP Pultec EQ's myself... electrics are so complicated...

Now, here is what I found out this afternoon. I'm a bit embarressed I must say, just because I didn't think of this earlier...  :-[
I cleaned both jack inputs with a small steel brush, and guesse what... after the cleaning the Vibro Champ was as quiet as a Vibro Champ can be (which is still not dead quiet, we all know that).

So the loud hum was bad contact in the jack inputs.

And seems now that my Weber power transformer is still working, so eventhough I allmost toasted it... I just re-insulated the green melted wire.

Anyone thinks this is crazzy that the PT still works? Because some people told me they were sure that the PT would be dead...

Anyway, my Vibro Champ works!

that is great!

amazing you figured out the input thing,

you might want to tighten the pots also so that they make good ground, this is an issue in old Fenders because of the dis similar metals, that brass plate on the steel chassis creates a small battery which sets up small currents which eat the metal and turn it into oxide,

Ok, I will check this later this evening!

Thanks again CJ for all the good help and time. Really appreciate this, as I know this is also time-consuming for you...

My best!