Aion Cirrus not working after build

[Linac Guy]

Hi All,

I just built an Aion Cirrus (Super Tube Screamer)
Link to project build (plans and parts)- https://aionelectronics.com/project/cirrus-ibanez-st9-super-tube-screamer/

Once I finished I plugged in the power and then to the guitar and amp, I got nothing!  No LED or sound.

1. I checked all solder joint and they look good
2.  went back over the board and checked the resistor values and they seem to be good
3. continuity check on all of the grounds (case to jacks, gnd on PCB, Gnd on 3pdt switch and back of power input jack) all beeped.
4. checked IC voltages and they are below
IC 1
1-3.45
2- 3.45
3- 3.3
4- -0.0
5- 0.0
6- 8.85
7- 8.87
8- 9.43

IC 2
1- 1.29
2- 1.27
3- 1.06
4- -0.0
5- 3.43
6- 0.81
7- 0.82
8- 9.43

Pictures have been posted to Imgur @ http://imgur.com/a/LvwGo

Your help and suggestions would be greatly appreciated.
Thank you

[jez79]

No LED resistor? There's no power getting to the LED without that. 4.7k is the usual, but depends on LED type/color and what you prefer.

[jez79]

C8 and C11 appear to be tantalum, but schematics ask for nonpolar. might not make a difference, try reorienting them.

More likely:
Your output jack is switched. You might have the output wire on the switched lug, try soldering the output wire to the other (non-sleeve) lug/pad

EDIT:looking closer, the output jack seems soldered at the right spot (that's the kind of troubleshooting error you hope for though...)

Check the 5-6-3 1-2-4 jumpers are well seated. They are correctly placed, but if they're not seated right no sound will go through.
Double check all your socket soldering underneath for all sockets.

[Linac Guy]

Hi Jez79,

Thank you very much for looking at it. I just posted 2 pics @ http://imgur.com/a/MU8yD

one of the parts list and the built PCB. Circled missing LEDR. The parts list doesn't include it as needed that's why I left it out, should I add a 4k7 resistor in there?

since the build I now have 100n box film caps for C8 and C11 so I will replace the tants with those.

Thanks

[Kipper4]

Something aint right with those voltages. All pins  1 2 3 5 6 7 should be around 4.5 v.

what voltage are you getting at Va (node between r18 r19?

ic1 pin 5 is grounded
ic1 pins 6 and 7 are nearly 9v
ic2 pins 6 and 7 look grounded too
something funky is afoot.


Did you rock it before you boxed it?

[slacker]

Kipper beat me to it   your voltages are very wrong. Check all the connections especially to pins 3 and 5 of both IC's, also check that the board isn't shorting out to something on the back.

[PRR]

"Va" should be +4.7V but appears to be 3.4V.

IC1 pin 5 should be Va but is dead-zero. Suspect short to ground here.

IC2B pins 6 and 7 should be Va not 0.8. I do not see a likely cause. It is possible that when this is cleared-up the "Va" will come-up to half supply (I suspect mis-bias of IC2B input is throwing R6 as an added load on Va).

[Linac Guy]

All, new pics posted here http://imgur.com/a/y641P

Ok here goes
1.   (pic) I took the board from the enclosure so I could replace C8 & C11 Tants to 100N Film Caps (thanks Jez79)
2.   (pic) Put in an LEDR resistor 4k7 (thanks Jez79)
3.   (pic) The Dual Pot didn't have a plastic cover over it and was pressed against the PCB. Touching all the leads sticking through underneath it!  I cut a piece of plastic (credit card) and put it between the pot and the PCB (thanks PRR, Slacker and Kipper).
4.   The LED is still not lighting up but has 9.43v w/switch pressed and 0v w/switch pressed again. What would cause the LED not to light up?
New Voltages
IC 1
1-   4.71
2-   4.71
3-   4.49
4-   0.0
5-   4.61
6-   4.71
7-   4.71
8-   9.43
IC 2
1-   4.71
2-   4.71
3-   4.70
4-   0.0
5-   4.70
6-   4.74
7-   4.70
8-   9.43
Do the voltages look better now that its not shorting? I haven't plugged the guitar into it yet to see if it works yet.
Please let me know what ya'll think.

appreciate the help!

[Linac Guy]

for clipping diodes I did the Zen Drive for D6-9 1n270 & 2n7000 then stock for D2-5

I also checked the jumpers and they are all seated well.

[aion]

Voltages do look good on this last run so I am optimistic that you'll have better luck this time!

Can you verify that the LED is the right orientation? (should be silkscreened on the bottom of the PCB) It's the only thing that you can't spot-check once it's mounted in the enclosure :)

[PRR]

Voltages look fine. (The odd voltage on IC1 pin 3 is meter-loading; it must be 4.71 when you are not poking it.)

Backward LED is possible. However on older LEDs I would expect 6V-7V when backward. Maybe the newer ones, or different colors, have backward-breakdown above 9V.

[Linac Guy]

Ok, just tested and...... Nothing

1. Checked the LED and it was bad so I replaced it
2. Now I get 2.6v at the LED with power on.
3. Plugged the guitar and amp into it. (Guitar into IN and Out going to Amp)
  a. No sound in bypass
  b. No sound when switch pressed (LED on) I do hear a pop from the amp when I press the switch.

Now I'm really stumped
Any ideas or things I could check would be greatly appreciated! Thanks

[slacker]

  a. No sound in bypass

That means you've got a problem somewhere between your jacks and the stomp switch. Your wiring looks ok from the photos, so first thing I would check is that the tip connections of the the jacks are not shorting out against the case, in the photos it looks the the input jack could be. Try rotating the jack so that the tip connection isn't facing the top of the case.
If that isn't the problem, plug a guitar lead into the input jack and use your continuity tester to make sure there is no continuity between the tip and ground. After that check that you have continuity between the tip and the square pad on the switch PCB and to the pad on the right hand bottom corner, the one diagonally opposite the square pad. If they are ok, then with the stomp switch in bypass (LED off)  check for continuity between the bottom right hand pad and the pad above it, the right hand middle one, and then from there to the tip of the output jack. Also check that there is no continuity between the tip of the output jack and ground.
That should pinpoint where the problem is.

[Linac Guy]

Slacker,

You were correct the tip was touching the enclosure.  Did I a continuity check between the case and the tip and beeeeeeeeep. Great eye, I completely overlooked that (total rookie mistake  ) and was trying to make the wires look clean and neat.

I will plug it in tomorrow and update y'all on how it works. I really appreciate all of the help!

Thank you!!

[Linac Guy]

Slacker, that was it! Thank you it works nicely.