Eros phono shunt regular voltage issue

[Hoosier]

Guys,
I didn't see another thread with a similar shunt regulator voltage issues, so here goes:
D6 - 368 V
D1 - 368 V
Both D2 LEDs light up but the D1 lights do not.
The 12BH7 tube does not light up.

I have double checked my work and don't see anything wrong, but I must be missing something.

Thanks in advance for any help.

Bob

 

[Paul Birkeland]

Hello Bob,

If the 12BH7 doesn't light up, that's the pivotal issue at hand.

What is the voltage at the +/- 6.3V pads on the power supply PC board?

(If it's 0V, don't go poking around on the board necessarily, just let us know)

-PB

 

[Hoosier]

It's 6.3 V.

 

[Hoosier]

PB -
When I was checking that voltage, I noticed the LEDs are lit and the tube is warmly glowing.  I'm not sure what was wrong, but the voltages check out fine now.  Thanks again for your time and the quick reply.

Bob

 

[Grainger49]

You likely have a loose solder joint.  Your poking them caused it (them) to make.  Turn the board over and check/retouch all the solder joints.

 

[Paul Birkeland]

If the 12BH7 didn't glow, but now does, there are a few possibilities.

One is a loose wire, as Grainger suggests, and this would have to be between the 6.3V power supply board pads and pins 4/5 and 9 of the 12BH7 socket.  You can check to be sure that these are tight and well soldered by tugging on them a little with your needle nose pliers.

I tend to find that it is more likely with this kit that there are metal bits between pins 4 and 5 on the remaining 3 9-pin tube sockets that are too close together, and potentially touching.  This would short out the 6.3V supply and also produce the symptoms you describe. 

 

[Hoosier]

Paul and Grainger,
  I have taken both of your pieces of advice and the voltages are checking out fine.  Thanks again for the help.

Bob