AionFX Lithium pedal - Has Power, No Effect

[sanzanobi]

The pedal power's on, and has a clean tone, but there's no effect when adjusting the pots. I went back in and reflowed most of the joints as well as passed the iron between joints to remove any possible shorts. The wiring looks correct based on the diagram. Any thoughts as to what might be the issue? Maybe a bad transistor or IC?

This is my 15-year old's second build. His first one (Super Fuzz clone) had some issues too, but we got it working thanks to some suggestions in the forum. Hoping you guys can help us track down the issue on this pedal too. Thanks in advance!

 

[Nostradoomus]

Did you bias the MN3007? Start by cleaning the board and checking all your joints, there are still some troublesome looking ones from this angle. What kind of voltages are you getting on your opamps/bbd?

white: looks like they are touching
red: good, for reference
green: potentially cold, not enough solder etc

 

[Stickman393]

Glanced over the build doc: Looks like he configured it for the MN3007, is that what's in the socket?

Also, there are jumpers underneath the BBD. They should be horizontally connected for the MN3007 Have ya pulled the BBD and checked those?

Not bad for a 15 year old.

 

[Nic]

Where did you sourced the ICs ? Mine did not work at first cause of a fake BBD.

 

[sanzanobi]

Thank you all for chiming in. I much appreciate it!

@Nostradoomus This morning I went through and cleaned the board, and touched the joints that you mentioned. I also adjusted the bias trimmer a half turn. No change in the pedal. I still get a clean tone in bypass and when the pedal is turned on. If there's more to biasing the MN3007, then I not sure what that entails (total newbie, but trying to learn). I'm also not sure how to check voltage on the IC's, but I'll try to find a tutorial on how to do that.

@Stickman393 Yes, the IC in that socket is a MN3007 chip. "They should be horizontally connected for the MN3007 Have ya pulled the BBD and checked those?" I'm not sure what you mean by this. Would you mind elaborating? I added the jumper based on the instructions and photos of the same build posted on the forum.

@Nic I purchased the MN3007 chip from AionFX. They're not particularly cheap for a component so I hope it's not bad. I only purchased one so I can't swap it out. The other IC's were purchased from Digikey. I swapped the OpAmps and the CMOS out one at a time to see if any were bad and the pedal is still not producing an effect.

 

[Nostradoomus]

Those were just examples of some to touch up, there are more. But You can adjust the bias in smaller increments left and right to try and find the sweet spot. Do you have a multimeter?

 

[sanzanobi]

Those were just examples of some to touch up, there are more. But You can adjust the bias in smaller increments left and right to try and find the sweet spot. Do you have a multimeter?

I did my best to reflow whatever looked like it needed it while I had the board pulled out of the enclosure. Yes, I have a multimeter.

 

[Nostradoomus]

Good news! So what you want to do is power the pedal up, set your DMM to measure DC Volts, clip the black test lead of the meter to ground and probe each pin of each opamp in the following pattern



Pin 1: 8.7v
Pin 2: 4.5v
Pin 3: 4.5v

etc for each chip.

 

[sanzanobi]

Good news! So what you want to do is power the pedal up, set your DMM to measure DC Volts, clip the black test lead of the meter to ground and probe each pin of each opamp in the following pattern

View attachment 90175

Pin 1: 8.7v
Pin 2: 4.5v
Pin 3: 4.5v

etc for each chip.

Ok, here's what I have:

IC1 (RC4558P - OpAmp)
1: 4.72v
2: 4.73v
3: 4.55v
4: 0.1mv
5: 4.67v
6: 4.69v
7: 4.65v
8: 9.36v

IC2 (MN3007 BBD)
1: 8.33v
2: 4.40v
3: 8.69v
4: 8.20v
5: 8.20v
6: 4.39v
7: 8.16v
8: 8.16v

IC3 (LM358N - OpAmp)
1: 1.829v - 1.840v (oscillated)
2: 4.31v
3: 4.26v
4: 0.1mv
5: 2.317v - 2.356v (oscillated)
6: 2.33v
7: 4.22v - 4.4v (oscillated)
8: 9.48v

IC4 (CD4047BE CMOS multivibrator)
1: 8.67v
2: 110.6mv
3: 7.59v
4: 8.83v
5: 8.83v
6: 8.83v
7: 0.2mv
8: 8.83v
9: 8.68v
10: 0.1mv
11: 4.40v
12: 4.39v
13: 0.1mv
14: 0.1mv

 

[Nostradoomus]

can you do the transistors as well? Q1, Q2, Q3. Lay their voltages out in the CBE fashion as printed on the board. Did you make any substitutions or are they 2n5088/87?

 

[sanzanobi]

@Nostradoomus Here you go! No changes to the transistors.

Q1 (2N5087)
C: 0.1mv
B: 8.52v
E: 8.49v

Q2 (2N5088)
C: 9.35v
B: 7.93v
E: 7.46v

Q3 (2N5088)
C: 9.47v
B: 9.47v
E: 8.82v

 

[sanzanobi]

can you do the transistors as well? Q1, Q2, Q3. Lay their voltages out in the CBE fashion as printed on the board. Did you make any substitutions or are they 2n5088/87?

Could it be that both transistor pin layouts are not CBE?

This is 2N5088. I can't tell if the diagram has the flat side facing toward or away.


There's no diagram on the data sheet for the 2N5087 transistor, but it does say (EBC) on the sheet.

 

[Nostradoomus]

If they are 5088/87 they are oriented correctly. Is that a bipolar cap in C14? looks like a little + sign on the right

 

[sanzanobi]

@Nostradoomus It's bi-polar. Here's a link to the capacitor.
https://www.digikey.com/en/products...IIwAYC0BTAxipBDJcAWAdmAE5gCuARmgC5IEAmIAugL5A

 

[Nostradoomus]

Something is going funky with your 3007, can you lift the mix pot and take a picture of the joints and jumpers there?

 

[sanzanobi]

Something is going funky with your 3007, can you lift the mix pot and take a picture of the joints and jumpers there?

You bet. Maybe I didn't add the jumper properly?

 

[Nostradoomus]

Bingo. Jumper these pads

 

[sanzanobi]

Bingo. Jumper these pads

View attachment 90209

Sweet. Guess we missed that in the instructions. It'll be tricky since the IC socket is in the way on the other side, but I'll get it done somehow. Thank you so much for all of your help. Very much appreciated!!!!

 

[Nostradoomus]

Solder it from the side you can see clearly, it shouldn’t be too bad

 

[sanzanobi]

Solder it from the side you can see clearly, it shouldn’t be too bad

Jumpers in place. I soldered them just like you mentioned, and unfortunately, still no effect.