Finished building - Passed resistance test, failed voltage. LEDs do not light up

[Drew495]

Hello!

As the title suggests, my recently built crack passed the resistance test but failed the voltage test. Additionally, the LEDs do not light up. When I tried plugging in my HD650s, I noticed a very loud buzzing with and without the RCA cables plugged in. When I tried to listen to music with them, I could actually hear it, but it was very distorted with a loud buzzing masking it. Obviously I did something wrong (this is my first time doing something like this) so any help would be greatly appreciated. If you need any extra information or pictures I'd be happy to oblige. I can't wait to hear how this amp sounds when it works! Here are the results for my resistance and voltage tests--keep in mind my multimeter is on the cheaper side:

Resistance:
1 - infinity
2 - infinity
3 - zero
4 - infinity
5 - infinity
6 - zero
7 - 3.03k
8 - 0
9 - 2.96k
10 - 0
12 - 0
13 - infinity
14 - 0
20 - 0
22 - 0
B3 - 3.03k
B6 - 2.96k
Center pin (red) - 89.8k
Center pin (black) - 97.9k
Ground tab - zero for both

Voltage (I measured this with my multimeter at 600 DC volts and 2000m DC volts, it will be displayed in that order):
1 - 0 and 106
2 - 0 and 115
3 - 0 and between 0 and 3
4 - 0 and 372
5 - 0 and 372
6 - 0 and 0
7 - 67 and infinity
8 - 0 and 0
9 - 70 and infinity
10 - 0 and 0

[Paul Birkeland]

As the title suggests, my recently built crack passed the resistance test but failed the voltage test. When I tried plugging in my HD650s,

The voltage checks told you your amp didn't work.  There is a very high chance that you can destroy your headphones by trying to listen to a broken amp, and the information you gathered by doing this is not helpful and not something we would ever ask for (or use).

Voltage (I measured this with my multimeter at 600 DC volts and 2000m DC volts, it will be displayed in that order):
1 - 106
2 - 115
3 - 0
4 - 372
5 - 372
6 - 0
7 - 67 and infinity
8 - 0
9 - 70
10 - 0

Just leave your meter on the high setting. 

Terminals 2 and 4 are connected by a wire, so their voltages can't be different.  The presence of some alarming voltages that are higher than what should be expected in the kit is pretty typical for loose ground connections.  The most common one is where the black wires meet on the headphone jack, as its easy to solder one of those two wires and miss the other one, leaving it loose in the jack. 

[Drew495]

Just leave your meter on the high setting. 

Terminals 2 and 4 are connected by a wire, so their voltages can't be different.  The presence of some alarming voltages that are higher than what should be expected in the kit is pretty typical for loose ground connections.  The most common one is where the black wires meet on the headphone jack, as its easy to solder one of those two wires and miss the other one, leaving it loose in the jack. 

Thanks for the help!

To clarify, the high setting is 600 DC volts, right? If so, why am I getting readings for only 7 and 9. Are all of my connections faulty and I'll have to resolder? What should my next steps be?

[Doc B.]

Recheck that all of your connections are correct and then reflow the solder joints, particularly the black wires at the headphone jack as PB has already pointed out. That is the first thing we would do if you sent the amp to us to fix.