Aion Refractor Issues - SOLVED

[cajone5]

Another swing and a miss.  I built this Klon clone (hopefully my last) and it's gated and has issues in bypass as well as on so my issue is likely around IC1, I think but not sure.  Anyway, I already verified all components and polarities although I could have made a mistake somewhere.  Voltages are off.  Even swapped IC's to no avail.  Will pull the board and reflow if I can't get any leads on the issue... My TL072 voltages look way off.

Substitutions:

C6 - 390n -- used a 330n and 56n in parallel
R12 - 422k -- used 470k and 3.9M in parallel





POWER: 9.5V
Diode voltages (cathode/anode)

Zener Voltage: 0 / 9.5V
D3 (1n4002): 13.59V / 9.5V
D4 (1n4002): 17.31V / 13.59V

IC 1: TLO72CP
Pin 1, 1.334
Pin 2, 1.334
Pin 3, 0.962
Pin 4, 0
Pin 5, 0.665
Pin 6, 1.083
Pin 7, 8.77
Pin 8, 9.50

IC 2: TLO72CP
Pin 1, -2.730
Pin 2, 0.472
Pin 3, 0.472
Pin 4, -9.14
Pin 5, 0.473
Pin 6, 0.471
Pin 7, 3.695
Pin 8, 17.31

IC 3: TC1044
Pin 1, 9.5
Pin 2, 4.918
Pin 3, 0
Pin 4, -4.424
Pin 5, -9.14
Pin 6, 4.651
Pin 7, 6.184
Pin 8, 9.5

[EBK]

Tantalum cap polarity?

[cajone5]

Tantalum cap polarity?

I didn't check that before but I did now.  Looks like that one's correct to me as well... hmm

[BrianS]

Can you post a picture of the bottom?  I feel your pain with this.  This has been the norm for me for the last 3 months.  Finally got the Cascadia working thanks to jubal (bonehead mistake on my part that he caught immediately). 

[gordo]

I checked against the scheme as well.  Gotta be a solder point or bad part.  I'll take a look at the resistors.  Very pretty build so troubleshooting should be pretty straight forward.

[cajone5]

I'll pull it apart and reflow/check for any shorts anywhere tonight.  Although those damn board mounted pots will make it a pain, hopefully it won't be too bad.  Will update once I have a chance to do that.

Thanks for the review!

[gordo]

Although those damn board mounted pots will make it a pain

Geez, in my world they make it SO much easier.  Pop the nuts, drop it out of the case....

[cajone5]

If it works they make it easier...

If they doesn't, it blocks the solder side of the board

[gordo]

Ah...ya, copy that.  You're right, its the only downside I can think of and a bugger with tight layouts.

[cajone5]

So I was able to slip away for a couple minutes today and took it apart, reflowed everything, and added another couple layers of electrical tape on the back side of the dualgang pot and it fired up just fine (as far as I can tell... had  to run it at super low volume due to guests in the house).

Looking at it again, I am guessing I had a slight short between something in the upper right corner of the PCB and the back of the gain pot which caused the issue.  Solder joints all looked good.  In any case, I spent way more time searching for incorrect parts or other issues than I needed to but it helped me speed up ad IDing resistors from the color bands.  So that's a plus...

Thanks for the help and hopefully it sounds good when I get a chance to get some volume going.