Crack LED issue

[barnstead]

First time builder here. I'm having issues with the LED on A3 which is failing to light up. The other LED does light and the voltages (below) appear to be correct. Any guidance would be much apreciated.

1. 75
2. 174.8
3. 0
4. 174.8
5. 58.7

6. 0
7. 103
8. 0
9. 93.7
10. 0

 

[Drew1d]

Do you have a picture of the 12au7 (9 pin) socket?

 

[Paul Birkeland]

Did you happen to build your Crack with the Speedball all at once?

 

[barnstead]

@Drew1d here's a picture of the 12AU7 socket.

@Paul No, I did buy the speedball but haven't touched it yet. It's just a standard Crack.

 

[Paul Birkeland]

Can you carefully measure the DC voltage at A3?

 

[barnstead]

I'm getting 0.03 volts through A3.

 

[Paul Birkeland]

Could you also post a photo of the octal socket wiring?

 

[barnstead]

Here it is, and one of the full amp.

 

[Paul Birkeland]

Can you check the DC resistance between A3 and terminal 3?  Does it change without the 12AU7 plugged in?

 

[barnstead]

I get 6 ohms between A3 and terminal 3 with the 12AU7 in and out.

 

[Paul Birkeland]

Are A3 and A4 touching at all? 

 

[barnstead]

No contact between A3 and A4.

 

[Paul Birkeland]

On the power transformer, remove the wires from terminals 7 and 9 and leave them poking up straight in the air then recheck the resistance between A3 and terminal 3.

 

[barnstead]

Still 6 ohms with the 12AU7 in and out and the wires out of transformer terminals 7 and 9.

 

[Paul Birkeland]

The most likely culprit here is that some debris has gotten into your socket and created a short between pins 3 and 4.  You may just want to e-mail replacementparts(at)bottlehead(dot)com to ask about getting a new 9 pin socket and some fresh LEDs.

 

[barnstead]

Thanks Paul. I will do that. Appreciate the guidance.

 

[Drew1d]

This is a simple vid on how I would check the diode and tube socket.  (not tube, as I said in the video)

 

[barnstead]

Thanks Drew, I missed your video earlier, but unfortunately no diode setting on my multimeter.

I did get the new socket in and installed it. But now the A8 LED won't light. Voltage measurements still look good.

 

[barnstead]

And here's the picture of the rewired socket.

 

[Paul Birkeland]

What are your current voltages?