Driver board testing

[sputnik0070]

Hello! I have looked through the other driver board testing threads and cannot figure out where I went wrong. The build went well up until the the driver board testing on page 65. On the A board I got a 518V reading on the IA, but when I touched the alligator clip to OA i got a spark and a reading of 0V. My readings for the D board were good (518V IA and 299 OA). I did not yet test 32U or 46U as I wanted to post first due to the spark making me nervous. I removed the mounting screws to try to see if any wires or leads were touching something they shouldn't, but didn't see anything out of place.
Thank you in advance for any guidance that can be provided.

Matt Nault

 

[sputnik0070]

I wanted to add that both 5670 tubes were glowing when powered up for testing.

 

[Paul Birkeland]

You'll have to power things back up and see if OA is still at 0V. If it is, we will have to see what the bottom of that board looks like, as well as the wiring around that tube socket.

-PB

 

[sputnik0070]

Thank you- I have some time over the weekend to power back up and take some photos.

-Matt N