No out in 12AU7 in 6 & 8 pin, is the tube damage.

[raymonyng]

Hi, is the tube damage, because the pin 6 & 8 are no out put.

[Paul Birkeland]

If you are testing the high voltage power supply, it would help to know the DC voltages on IA, IB, OA, OB, KregA, and KregB.

If the shiny silver coating inside the glass of the 12AU7 has turned white, then it's damaged.  Otherwise the issue is more likely to be with what has been constructed.

[raymonyng]

Thanks for help, the
IA.  298v
IB.  298V
OA.     0V
OB.  215V
KA.      0V
KB.      3V
And the B side both the led is light.

[raymonyng]

Also there’s no power measured in the MEJ5731 body.

[raymonyng]

And I check the power from B1 go through the led transistor led until to the MEJ5731 both side then in the middle pin there’s no power anymore.

[Paul Birkeland]

OA.     0V

This would have me suspicious that the wrong R1 resistor is installed on that side of the board or there's a soldering issue on the bottom of the board.  There may also be a jumper that isn't located correctly. 

Could you post some photos of the board?

[raymonyng]

Sorry, I don’t know how to summit the photo, they say hit the Alt+S, how to do?

[raymonyng]

Now I change the led in the A side and the voltage comes out are
IA.     270
IB.     270
OA.    133
OB.    215
KA.        0
KB.        3V
What I next to check?

[Paul Birkeland]

Please post photos of what you have built so far. 

[raymonyng]

I want to summit photo, but don’t know how to summit, it’s say alt+S, where can I found the key alt+s?

[Paul Birkeland]

Hit "reply" then "attachments and other options" and upload your pictures there.

[raymonyng]

After so many days, now the reading are
IA.       260
IB.       260
OA.      215
OB.      153
KregA.     7
KregB.    10


IA.       153
IB.       215
OA.      146
OB.      145
OC.      141
OD.      143
OKA.    143
OKB.    140
OKC.        0
OKD.        0
Then still work hard to try to fix it, thanks for you help.

[Paul Birkeland]

Can you please post some photos of your build.

[raymonyng]

Here’s are the photos

[Paul Birkeland]

I would watch this video:


I see some joints that aren't really soldered, many cold joints, and some that really could use a little more heat.  Also be sure you are using 60/40 leaded rosin core solder.