Mini Me – No output (solved)

[Billy]

I think you may now have a grounding fault could you post another pic of the board as it is now so that we can clearly see your wiring

I’m not sure what you mean when you say

I grounded the white hole to the top left G hole on the 3PDT

 

[Anonymous]

Hopefully these pictures will convey what I seem to not be able to. Thank you for looking and helping.

 

[Billy]

Your solder joint to ground on the bottom of the main pcb looks like it hasn’t made a good connection to the solder pad reflow that so you get a nice joint fusing the wire and pad together

Did you solder the MN3007 jumpers in place on the underside of the board I’ve assumed you have but thought I’d ask just in case you’d overlooked them

If none of the components are fried we’ll defo get there do you have any spare ICs etc

[Anonymous]

Good call there, resoldered that joint and put the ICs back in. The bypass works now without any loud clicks while engaging and no more stun gun sound. While engaged however, the output is just slightly more warm and boosted than the clean tone. I played a riff into a looper and ran it thru the pedal while turning the TR1 about 10 degrees each turn for a full 180 degrees and fiddling with the Depth/Rate. No changes in sound at all while doing this. I just don’t get what’s going on.

I did solder the jumper on the backside of the board as well as the transistor sockets and IC sockets.

Unfortunately I have no other ICs at this time besides what I have in other pedals which I supposed I could take out to test and hopefully get this figured out.

Thank you, big time. We’re making progress, let me know what else I can do and I’ll get it done.

 

[Billy]

What to do albeit a pain is once again post all voltages

Also check your power in on the +9v and ground pads then +9v points especially into lug 3 of TR1 if you’re not sure which is 3 just check you get 9v to one of the outer pins or continuity check those pins to ground you want the one not connected to ground

As Cybercow said TR1 has a very small sweet spot so turn it a millimetre at a time, starting with it just before half way

Do all your tests with depth maxed rate around half way

Check you get a pulsed voltage at pin 7 of IC4 the LFO

Continuity check between IC3 pin 10 and IC2  pin 6 and IC3 pin 11 and IC2  pin 2 this is the clock connections from IC3 to IC2

If you get no chorus by adjusting TR1 the problem could lie in the parts that affect the wet signal the basis of it being IC4 the LFO which modulates the signal, intensity via depth and speed via rate that in turn drives IC3 which produces the dual clock signal to IC2 which delays the signal before it’s mixed with your dry signal, so we’re checking the wet signal components, as it appears the dry signal via IC1 is ok

With the changes checking voltages again may point us in the right direction with IC4 initially being in the wrong way im wondering if it has damaged IC3

CMOS chips are easily susceptible to damage although I’ve never had one go bad but apparently they’re more prone to damage by static etc than other chips

Anyway once we see the voltages it may reveal something

 

[Anonymous]

Thanks for the response, it was very helpful.

Updated voltages with settings how you described them.
IC1-
1. 4.6
2. 4.6
3. 3.6
4. 0
5. 4.5
6. 4.6
7. 4.6
8. 9.2
IC2-
1. 7.9
2. 4.2
3. 5.6
4. 7.5
5. 7.5
6. 4.2
7. 7.5
8. 7.5
IC3-
1. 8.3
2. .08
3. 7.1-7.3 fluctuating
4. 8.5
5. 8.5
6. 8.5
7. 0
8. 0
9. 0
10. 4.2
11. 4.2
12. 0
13. 8.2
14. 8.5
IC4-
1. 1.5-2.2 fluctuating
2. 4.2
3. 3.9
4. 0
5. 1.8-2.8 fluctuating
6. 2.2
7. 2.2-6.1 fluctuating
8. 9.2

[Billy]

Where did you get your MN3007 from

All other ICs are in the ballpark except IC2

Double check your jumpers on IC2 for the 3007

*edit  orient BBD jumpers as shown in the build doc images below

[Anonymous]

All components were included in the kit I bought here.

 

[Barry]

I am sorry but are we all looking at the correct build document?

The one needed is the 2020 version which is listed on the Shop page as well as the Masterlist on the guides page which shows clearly how to use the Jumpers. The other doc is for a previous version that would only allow for the MN3007 chip and nothing else.

https://guitarpcb.com/wp-content/uploads/2018/06/Mini-Me-2020-Build-Document.pdf

[Billy]

Jumpers go like this as illustrated in the correct build doc just ignore my previous incorrect jumper placement info and use this image as you can see the MN3007 jumpers are vertical not horizontal as previously stated

I’ve edited out previous posts to avoid any confusion

With the other faults rectified hopefully when you put your jumpers in it’ll spring to life

 

[Anonymous]

I assume I have the 2020 version since I ordered it two weeks ago, it looks like the PCB has the holes under the socket to do jumpers and the IC is the MN3007 which is ideally the one to use as it is the only one I have.

So correct me if I am wrong but this is my understanding of next steps: remove IC from socket, run a jumper from 1->3 and 2->4, replace IC, test voltages and pedal. I looked through the guides lists and did not find a jumper guide in any of them but my understanding is that a jumper is just a short wire soldered from one hole to another. Correct? I did add a jumper, or at least what I understand to be a jumper, to D4. That is correct right? The PCB printing shows diode markings there but there was not an included diode for it.

I just want to confirm everything before acting because to implement these changes I would have to remove everything from the enclosure again and I want to avoid that if I can. If this is correct then I’ll be happy to take it out and add jumpers.

Thanks you guys and sorry for any confusion this may be causing. I really appreciate all of the help.

[Anonymous]

So is it better to use a short stem from a resistor or an actual wire?

[Barry]

The Jumper pictures above are from the correct manual. Both are listed.

I have not checked Musikdings site to be sure what version they have listed but i will.

Here is the link to be sure:

https://guitarpcb.com/wp-content/uploads/2018/06/Mini-Me-2020-Build-Document.pdf

You can use whatever type of Jumper you want since it is not going to touch anything else. No difference.

 

[Anonymous]

Jumpers in place:
IC2-
1. 8.5
2. 4.2
3. 5.6
4. 0
5. 0
6. 4.2
7. 5.9
8. 5.9

AAANNNNDDDD IT WORKS!!!!

I turned TR1 about 2mm to the left and it was a little bit more chorusy. As described. Thank you guys all SO much for helping me get this running.

[Billy]

Excellent glad you’ve got it going

That was interesting to say the least a few wee problems sorted and then the wrong build doc linked to throw something else into the ring!

Troubleshooting can be very frustrating but hopefully it will stand you in good stead in any future debugs, rectifying a fault then retaking voltages is always good for highlighting problems, in this case it definitely led us to the final fault which stood out like a sore thumb with your final voltage readings

Well done to you for your perseverance I’m so happy the MN3007 wasn’t zapped I was going to say it should be ok it can take up to -15v but I wasn’t gonna tempt fate!

 

 

 

[Cybercow]

Thor – excellent news! Your patience on this has been impressive. And Billy’s tenacity in assisting you has been equally outstanding. Welcome to Online Troubleshooting 103!

[Barry]

Congratulations!  The Mighty Thor!!!

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