Weird resistance and voltage [resolved]

[yun]

Hi, all.

I just finished assembling the kit, which is based on v1.1, but I have weird resistance value and voltages.

For resistance, most of terminal looks good, but the T6's value has really wide range. Sometimes, it is 0 as expected, but sometimes it is 16M Ohm or 8M Ohm, and when it is not zero, it is keep increasing.

I thought that it was my DMM issue, so I proceed to voltage check. But it looks there are more problems on it.

T1 - 50~100V   --> 150V
T2 - 170V         --> 170V
T3 - 0V            --> 0
T4 - 170V.        --> 170V
T5 - 50 ~ 100V -->150V

T6 - 0V.           --> 100V
T7 - 90~115V  --> 110V
T8 - 0V           --> 0V
T9 - 90~115V. --> 110V
T10-0V           --> 0V

For T1 and T5, obviously, it is out of the proper range, and T6 is totally failed. Both tiny red LEDs are working well.
Can anyone lit the path which I should check?

Thanks in advance.

[Paul Birkeland]

I would double check to see if one of the black wires on the headphone jack is not well captured by solder.

Do both tubes glow? 

[yun]

I would double check to see if one of the black wires on the headphone jack is not well captured by solder.

Do both tubes glow?

Hey, thanks for replying. Yeah. Tubes are all glowing well.

[Paul Birkeland]

It's very likely that you have a loose solder joint in the amp.  Terminal 6 and terminal 10 get their ground reference from the headphone jack, so that would tend to suggest that the solder joint on the headphone jack where the two black wires meet may not be well soldered.

The problematic voltages at terminals 1 and 5 combined with the LEDs illuminating would also be consistent with a loose solder joint where the black wires meet at the headphone jack.

[yun]

It's very likely that you have a loose solder joint in the amp.  Terminal 6 and terminal 10 get their ground reference from the headphone jack, so that would tend to suggest that the solder joint on the headphone jack where the two black wires meet may not be well soldered.

The problematic voltages at terminals 1 and 5 combined with the LEDs illuminating would also be consistent with a loose solder joint where the black wires meet at the headphone jack.

You are right!! After re-soldering the upper lug on the headphone jack, it works!!! Thanks bro!!!!