LEDs not lighting Help Please (solved) New C4S Board

[thdewitt]

OK, here are the readings without the EL84 plugged in.
IA 180, OA 127, OB 120.  So they really did not change.  Is that strange?  What does that mean?  What does the EL84 do?

Thanks,
Tom

[Paul Birkeland]

Can you confirm that the R1 resistors are the correct values?
 

Unplugging the EL84 removes the high voltage regulator from functioning in the circuit, which just leaves us with a couple of C4S's and the 300B.  For whatever reason, your 300B on that side is not drawing proper plate current, and I believe we have it narrowed down to an issue on that C4S board.

-PB

[thdewitt]

They seem to be fine.  Should i take them out to measure.  The numbers are good and I usually measure when installing them.

(https://dl.dropboxusercontent.com/u/38833957/2015-01-20%2014.03.37.jpg)

[Paul Birkeland]

I'd have a long look at the jumper and solder joints on the bottom side of the board, as well as around the 4 pin socket.  You may also want to be sure that pin 3 of that 4 pin socket shows 0V when the BeePre is on.

-PB

[thdewitt]

OK, now I am really frustrated.  I took the CS4.  Put in new jumpers following the directions in the manual.  While it was out, I carefully inspected the manual pages and the 4 pin to make sure it is right.  I did notice that the wires on pin A1 and B4 are the only ones that are not symmetrical but that is the same as the manual.  I reflowed all the joints on the 4 pin and surrounding connections.  I reflowed the CS4 again.  I then put it back together and there was no change.  The LED's are still not lighting.  I am stuck.  Are there any readings I can take to further check the board to find if one of the components are faulty.

Tom

(https://dl.dropboxusercontent.com/u/38833957/2015-01-20%2015.38.14.jpg)

[thdewitt]

I also put in a good 300b from my paramounts. The voltage at b3 is zero while on. 

[Paul Birkeland]

Try reheating the center leg of the MJE5731A on the B side of that C4S board.

[thdewitt]

Ok.  But I have reheated them all twice. 

[thdewitt]

OK, I did it.  The led's still not lit.   

[Paul Birkeland]

Heat the solder joint at 11 and remove the wire heading back to the EL84 so that it's out of the t-strip and floating in the air, then retest.

[thdewitt]

Hello, before I got your last post, i removed the whole C4S and swapped to the other side.  So now the problem has moved to the other side so it is definitely in the wiring of the board or something on the board.  The C4S moved to the B side worked fine.  So the problem followed the board.  Should I still try the test that you just posted based on the new information.