Crack not glowing on startup - shorted diodes? [solved]

[Paul Birkeland]

1) Terminals 6 and 10 don't seem to settle on a value, it's always moving up and down, but don't seem to go beyond + or - 10, which I assume is within the 15% safe limit, right? Just wanting to be sure that the fact that it never stops moving isn't a bad sign.

I do have an mV symbol as Caucasian Backplate mentioned, but it seems like it's always on. To clarify, I'm testing DC volts.

If you have a 10 on your meter, and mV shows up, that's 0.010V, which is very close to 0.  If your meter has scales, and you are on the mV scale, then that will also be 10mV.

2) Terminals A1, A6, B1, and B4, which should be 90, are getting 74-76 instead. Is this too far off?

That's indicative of a stronger than normal 12AU7.

3) And finally, would it be worthwhile to complete the headphone jack grounding mod before moving forward?

Don't modify an amplifier that you aren't sure is working.

 

[Todd]

• Holy smokes, guys! It works, and it's glorious!
  
  Thanks so much for all of your replies. All of them were very helpful in helping me get it straightened out.
  
  The only thing left for me to do is to pick a stain and assemble the housing.
  
  I'll also be selling off my Fiio e09K + e17 combo and will likely be upgrading to a Schiit Modi 2 Uber for a DAC.
  
  I was able to test the Crack using Sennheiser HD600s by connecting the Crack to the Fiio e09K + e17 combo, and from that to my PC.
  
  I'll update the original post with my solution for any other novices stumbling across this thread looking for help, but in short, taking note of these amateur mistakes may do the trick:
  
  • Reflow and add more solder to any of your potentially suspect looking joints. Flip the board to see if the joints look good from the other side.
  • Use alligator clips so that your multimeter probes don't move--I got sparks without one.
  • If you see an mV on your multimeter when testing voltages, it means milivolts, 1000 mV = 1V, so your larger looking numbers may be perfectly fine.