Voltage at Step 36

[birddogstudios]

Upon completion of my C84 Revision 2 preamp, I am seeing the wrong voltage when tested.

Step 36 states you should see +14v across PGND and +B. I am seeing -6.55v.

On step 37, I am seeing the correct voltages across PGND and -B. I am seeing -14.5v


I did search the forums pretty thoroughly and these two posts seem to have the same problem as me. Unfortunately, their fixes are not problems in mine (i.e. I've checked what they configured wrong and I have not done the same thing). Both of these posts saw a negative voltage on step 36, much like my problem.
viewtopic.php?f=8&t=1920
viewtopic.php?f=8&t=1902


What I've tried so far.

- Checked all diodes to be oriented properly. They are correct.
- Checked caps C34, C38, C31, and C35 to be oriented properly, they are.
- Checked for shorts around U5 and U6, there don't appear to be any.
- Check U5 and U6 to make sure I didn't get these mixed up, they are in the right places and oriented properly.
- Checked all chips Q1 - Q10 for proper orientation, they are put in the right way.
- Checked all solder joints with a magnifying glass. I did see a possible short between D1 and D2 but tried to alleviate the problem. Same result upon testing after cleaning up the joint.
In your expert opinion Tim, could a diode short have caused this issue?

Anyone have any suggestions?



I am going to go back over the unit tonight and triple check cap orientation, etc. etc. etc.

I really don't want to have to send the unit back for rebuild, mainly because I love to build 7th circle pres and will be questioning my own ability to complete one of these projects in the future. I definitely feel like a failure. I have successfully built 3 press (2 t15s and 1 c84, rev 1.9.1, which was a seemingly easier).

[birddogstudios]

I just went through and re-checked every component. Capacitors, IC chips, PNPs & NPNs, Qs, Us, you name it, I checked that it was in the correct spot and that if need be, was oriented properly. All of my components are good but I'm still getting the reading of -6.55v on the +B.