So, I built a Madbean Current Lover 2015 (http://www.madbeanpedals.com/projects/CurrentLover/CurrentLover_2015.pdf (http://www.madbeanpedals.com/projects/CurrentLover/CurrentLover_2015.pdf)) ...
- it worked fine on my testing rig before boxing
- once boxed, it gave either silence (no signal) or ear-piercing tone when I operated the stomp switch
- probed it: faint testing rig tone when not touching the probe to the circuit and ear-piercing tone everywhere when I probed
- pulled it out of the enclosure
- checked parts and wiring
- re-ran testing rig:
- faint testing rig tone in bypass, silence when engaged
- probed and got input tone at input pad, but nowhere else
- took pictures and recorded voltages:
(http://imageshack.com/a/img923/3462/40HhUb.jpg)
(http://imageshack.com/a/img924/116/vfAULq.jpg)
(https://imageshack.com/i/poh7h52Hj)
- followed Madbean forum advice:
- checked parts and wiring
- reflowed solder joints
- continuity-tested and short-checked all jumpers and off-board wiring
- replaced all ICs and transistors with new ones from Small Bear
- re-ran testing rig:
- clean tone in bypass
- clean tone when engaged
- recorded voltages with new chip set:
(http://imageshack.com/a/img924/7093/c5KdTn.jpg)
Current status: using "S" and "R" to send and return signal to the PCB from testing rig, I get a clean signal only at "R" no matter how many times I follow the biasing instructions. Rate light is flashing.
I'm not getting any responses on the Madbean forum (http://www.madbeanpedals.com/forum/index.php?topic=23954.msg235099#msg235099 (http://www.madbeanpedals.com/forum/index.php?topic=23954.msg235099#msg235099)). I'd really appreciate any help or direction for further troubleshooting or fixes.
Thanks!
I'm looking at your voltages on pin 3 of the two 4558 chips. Should be the same.... Somehow, your V_B is not correctly making its way from IC7 to IC1.
Double check those resistors in the lower right corner of the board. Also check continuity between the right side of R4 and pin 3 of IC7.
And check to see if you have a measurable voltage drop across R4. Nevermind that. You do. Something is possibly shorting to pin 3 of IC1, causing too much current to flow through R4.
Thanks for your suggestions Eric. I really appreciate it! I'd really like to get this circuit running again.
Unfortunately, I've double-checked the resistors in the lower right corner of the board and verified continuity between the right side of R4 and pin 3 of IC7.
Is there something else I could check?
Let me just check to see if I got this bit right:
1. Everything worked (unboxed)
2. You boxed it, and it stopped working.
3. You unboxed it, and it didn't come back to life.
Correct?
I'd suggest reflowing your solder on your pots and toggle. If PCB mounted parts are not perfectly aligned, boxing up the board can subject the solder joints to significant mechanical stress. You may have already done the following, but I'll write it anyway: board-mounted pots and switches should be tightly mounted to the enclosure first, then the board should be soldered to them.
If that isn't the issue, we can keep thinking. :icon_wink:
Can you provide links to higher resolution pics?
Mentioned this on the other forum and got no response.....
Any reason why you have 9V on Pin 13 of IC4 and 0V on Pin 12? Looks like that is either a typo or a problem.
Also, when you are reading voltages on this, make sure you do it in Filter Matrix mode. Also, turn the Rate control all the way CCW.
Quote from: Govmnt_Lacky on December 08, 2016, 09:37:19 AM
Mentioned this on the other forum and got no response.....
Any reason why you have 9V on Pin 13 of IC4 and 0V on Pin 12? Looks like that is either a typo or a problem.
Also, when you are reading voltages on this, make sure you do it in Filter Matrix mode. Also, turn the Rate control all the way CCW.
I wouldn't be too concerned about those IC4 voltages. Those pins appear to be unused anyway, and the stated values would only be guaranteed if at least one clock pulse (one rising edge) reached the clock input (here, the clock is tied to ground).
Quote from: EBK on December 08, 2016, 08:04:13 AM
Let me just check to see if I got this bit right:
1. Everything worked (unboxed)
2. You boxed it, and it stopped working.
3. You unboxed it, and it didn't come back to life.
Correct?
I'd suggest reflowing your solder on your pots and toggle. If PCB mounted parts are not perfectly aligned, boxing up the board can subject the solder joints to significant mechanical stress. You may have already done the following, but I'll write it anyway: board-mounted pots and switches should be tightly mounted to the enclosure first, then the board should be soldered to them.
If that isn't the issue, we can keep thinking. :icon_wink:
Can you provide links to higher resolution pics?
Thanks for following up Eric. Almost right ...
1. Everything worked (unboxed)
2. I boxed it and everything worked through testing rig before stomp and DC/IN/Out jacks were connected
3. I connected the switches and jacks and it stopped working.
4. I unboxed it and it didn't come back to life.
5. I switched all ICs and it still didn't come back to life.
I didn't mount the pots or toggle in the enclosure before soldering them to the board, but I did reflow after installing the board in the enclosure (between steps 1 and 2, above). I also checked parts and reflowed everything after step 4, above.
Not sure if these pics are higher resolution?
(http://imageshack.com/a/img921/2060/RGv7B3.jpg)
(http://imageshack.com/a/img924/3126/kCTb5a.jpg)
I'll try to take better pictures in daylight tomorrow.
Thanks again!
Quote from: Govmnt_Lacky on December 08, 2016, 09:37:19 AM
Mentioned this on the other forum and got no response.....
Any reason why you have 9V on Pin 13 of IC4 and 0V on Pin 12? Looks like that is either a typo or a problem.
Also, when you are reading voltages on this, make sure you do it in Filter Matrix mode. Also, turn the Rate control all the way CCW.
Thanks for ideas Govmnt_Lacky. I saw your original post on MB re: website problems, but not the addition re: voltages. Sorry.
I double-checked this evening and I've definitely got 9V on Pin 13 of IC4 and 0V on Pin 12. Urgh. Is it possible to trace this problem back to a source issue using my audio probe or multimeter? I'd welcome any ideas. Thanks again!
Oops: addition re: the switch: I've been taking voltages with pots, trims and switches set per the calibration instructions. They say switch right which I think is flange mode, not filter matrix. Should I retake my voltages with the switch left?
See above. Your IC4 voltages are fine. :icon_wink:
To clarify, those two pins are locked in an arbitrary state because that flip-flop is unclocked. Your arbitrary state just happens to be the opposite of madbean's arbitrary state. Treat them as a logical "Don't Care" because they aren't connected to anything in the circuit.
If you really want those voltages switched (perhaps just to convince yourself that the flip-flop isn't fried), bend pin 11 up, resocket the chip, power it up and give pin 11 a 9-volt pulse.
More info gathering.
1. Voltages were all measured unboxed on your test rig?
2. Is there any chance at all you accidentally reversed the polarity of your DC jack when you boxed it up? Think very carefully about this one and retrace your steps.
3. No clean signal when effect was engaged and in the box?
4. Currently, clean signal comes through just fine at output when the effect is engaged?
Measure the voltage to the left of C1. Should be 0. (Wondering if C1 is shorting or super leaky).
Thanks again Eric for following up.
Quote
1. Voltages were all measured unboxed on your test rig?
Yes, all the voltages posted were measured unboxed on my test rig.
Quote
2. Is there any chance at all you accidentally reversed the polarity of your DC jack when you boxed it up? Think very carefully about this one and retrace your steps.
I can't say there's NO chance that I reversed polarity. :-[ I've since changed the power leads since and have no pictures of it boxed, so there aren't any obvious indicators, but I'm pretty sure I metered it boxed to verify DC and GND. Not absolutely 100%, mind. Would reversed polarity have caused the circuit to shriek like it did?
Quote
3. No clean signal when effect was engaged and in the box?
When it was in the box it gave either silence (no signal) or ear-piercing, shrieking tone when I operated the stomp switch ... but I wasn't sure which was engaged and which was bypass. :icon_redface:
Quote
4. Currently, clean signal comes through just fine at output when the effect is engaged?
Yes, and sounds just like bypass. The rate indicator is also blinking and changes tempo when I adjust the rate knob.
Quote
Measure the voltage to the left of C1. Should be 0. (Wondering if C1 is shorting or super leaky).
The left side is 0 VDC, very occasionally 0.1 VDC.
Is any of helpful? Anything else that I should do or check?
Is anything currently different now connection-wise from when it originally worked, i.e., do you have a switch or jack connected now that wasn't there originally?
I should probably confess that at this point I haven't yet run you through any sort of methodical debugging procedure on this circuit. I'm shooting from the hip here, for the time being. :icon_cool:
But, if you don't mind this approach, I do think we are making some sort of disorderly progress. Ideally, I'd like to get things back to working unboxed and take a long pause.
Quote from: EBK on December 09, 2016, 10:14:18 PM
Is anything currently different now connection-wise from when it originally worked, i.e., do you have a switch or jack connected now that wasn't there originally?
I should probably confess that at this point I haven't yet run you through any sort of methodical debugging procedure on this circuit. I'm shooting from the hip here, for the time being. :icon_cool:
But, if you don't mind this approach, I do think we are making some sort of disorderly progress. Ideally, I'd like to get things back to working unboxed and take a long pause.
Getting things back to working unboxed and taking a step back sounds great. That would be a major achievement for me!
Ooops! EDIT: you asked about different connections from when it worked (not from when boxed). Sorry. Answer changed:
The only additional connections from when it worked are the 4 disconnected stomp leads other than Send and Return.
(http://imageshack.com/a/img924/6121/dEmRvb.png)
When I had it operating, there were only jumper, DC, Send and Return leads.
Wait. So, when it worked, you had send jumpered to return, and you had an input and output jack, right (no send/return jacks)?
Quote from: EBK on December 10, 2016, 11:01:26 AM
Wait. So, when it worked, you had send jumpered to return, and you had an input and output jack, right (no send/return jacks)?
Nope? I don't THINK so? I meant that the only leads attached to the PCB at the time it worked were the ones not crossed out in this picture:
(http://imageshack.com/a/img924/34/Btvowl.jpg)
I think the PCB In and Out are labelled S (Send) and R (Return) because the PCB jumpers them to separate solder pads for the input and output jack leads. Does that make sense?
Quote from: brucer on December 10, 2016, 02:37:48 PM
Quote from: EBK on December 10, 2016, 11:01:26 AM
Wait. So, when it worked, you had send jumpered to return, and you had an input and output jack, right (no send/return jacks)?
Nope? I don't THINK so? I meant that the only leads attached to the PCB at the time it worked were the ones not crossed out in this picture:
(http://imageshack.com/a/img924/34/Btvowl.jpg)
I think the PCB In and Out are labelled S (Send) and R (Return) because the PCB jumpers them to separate solder pads for the input and output jack leads. Does that make sense?
It's actually making less sense. The schematic shows 4 jacks: input, output, send, and return. You appear to be telling me that you were not using an input or output....
I'll take a closer look later at the wiring options in the project file to see if I can figure out what you did.
Thanks! The wiring diagrams posted in this thread are the ones I followed, the one with crossed out leads leads for testing and the full diagram for boxing.
Getting closer to understanding this board.
Looking at the bottom edge of the board, the "bypass" pads are labeled G L S + - I R O:
Ground
LED
Send
(+) LED anode
(-) LED cathode
Input
Return
Output
But, I see on the schematic what you are saying about the input and output being S and R. So, I and O are merely the jack designations, not FX In/Out, like I assumed, and to make matters worse, S and R have nothing to do with the send and return jacks in the schematic! :icon_eek:
This really seems to defy convention, but armed with this new understanding, I can take a better look at what you did.
My current best guess as to what went wrong is that you may have had your stomp switch rotated 90° when you wired it up. Now we just need to figure out what the consequences of that would have been....
Do you still have the stomp switch wired up?
Thanks Eric. I'm a little relieved that I've at least been using the correct leads for testing! Unfortunately, the stomp is no longer wired up. I detached it from the PCB leads when I pulled the PCB from the enclosure. However, it's still mounted in the enclosure and looks like the "normal"orientation (lug openings point to top and bottom of the enclosure)?
(http://imagizer.imageshack.us/v2/640x480q90/923/UuaFv6.jpg)
(http://imagizer.imageshack.us/v2/640x480q90/921/0m5Jfh.jpg)
Is there anything I can check on the board to see what I've damaged or done incorrectly?
Check to make sure you didn't short any of those bypass pads together.
When you replaced the chips, did you replace all of them? Where did you get your MN3007 from?
Thanks Eric. I've checked all the bypass pads with a multi-meter and none of the adjacent pads are showing continuity with one another. Re: the chips, I did replace them all with new ones from Small Bear (incl. the MN3007).
Back again and still saying you need to explore why it is that you have 9VDC on Pin 13 of the CD4013 clock.
If you look at the datasheets, there is no logical reason why Pin 13 should have any voltage on it (same goes for Pin 12 which I can only assume is a typo on the madbean build doc) as all of the other pins for that logic have 0V :o
Have you checked to see if you have a short between Pins 13 and 14 (with the chip removed) on IC4?
I'm not saying its the root of your problem BUT... it could certainly be one of the causes.
Please follow my bending pin 11 up suggestion from December 9th and report your voltages.
Thank-you both. I'll try my best to do as you suggested tonight.
Regarding bending up pin 11 on IC4, re-socketing, applying 9V, bending pin 11 back, re-socketing and reporting voltages, is it enough to use a 9V battery, ground the negative lead and touch the positive lead to pin 11 on IC4 just once?
(sorry for the newbie question, I just want to get it right and not make things worse)
Thanks again.
Quote from: brucer on December 12, 2016, 05:14:34 PM
Thank-you both. I'll try my best to do as you suggested tonight.
Regarding bending up pin 11 on IC4, re-socketing, applying 9V, bending pin 11 back, re-socketing and reporting voltages, is it enough to use a 9V battery, ground the negative lead and touch the positive lead to pin 11 on IC4 just once?
(sorry for the newbie question, I just want to get it right and not make things worse)
Thanks again.
Just run a wire from your +9v spot on your board and briefly touch it to pin 11. Actually, though, I maintain that this is not a meaningful test. We'll instead test the half of that chip that is actually connected to something. More on that later.
Quote from: Govmnt_Lacky on December 12, 2016, 01:45:09 PM
Back again and still saying you need to explore why it is that you have 9VDC on Pin 13 of the CD4013 clock.
If you look at the datasheets, there is no logical reason why Pin 13 should have any voltage on it (same goes for Pin 12 which I can only assume is a typo on the madbean build doc) as all of the other pins for that logic have 0V :o
Have you checked to see if you have a short between Pins 13 and 14 (with the chip removed) on IC4?
I'm not saying its the root of your problem BUT... it could certainly be one of the causes.
I've looked at the data sheet. Pins 12 and 13 are flip flop outputs, and one will always be logical HI (9 volts in this case), and the other will be logical LO (0 volts). The state of those pins is determined on a rising edge of a clock pulse on pin 11. If there never is such a rising clock pulse on pin 11, then pins 12 and 13 are left unchanged from whatever initial (arbitrary) state they are in at power up. It is not possible for both pins 12 and 13 to be at 0 volts. The madbeans measurements of those pins and brucer's measurements are equally valid and consistent with proper operation of that chip. Moreover, the arbitrary nature of those pin voltages presents no possible source of error in this circuit because they are not connected to any other part of the circuit, i.e., that half of the chip is unused.
I've been very tied up with holidays + family, but got back to troubleshooting this circuit last night. Unfortunately, I had little success.
Re: Govmnt_Lacky's concerns/suggestions around IC4, I confirmed that I don't have a short between Pins 13 and 14 with the chip removed (Yay!!).
Re: EBK's thoughts about flip/flopping voltages on pins 12 and 13 of IC4 by momentarily touching a 9v supply to a bent up pin 11:
- I tried once and was unsuccessful in flip/flopping pins 12 and 13 on my currently installed CD4013;
- I tried again and broke pin 11 off my currently installed CD4013 when bending it back into position (URGH!!);
- I installed the second CD4013 that I have on hand and it had the opposite pin 12 and 13 voltages from the first CD4013 that I tested.
Sooo ... not exactly the direct test of EBK's thoughts on flip/flopping pins 12 and 13, but suggestive that he's correct.
In any event, I still have clean signal only through the circuit and voltages are still the same as on the "Chip Set #2" page in my original post except that pins 12 and 13 of IC4 are now reversed.
I'd really appreciate it if anyone has some other thoughts on troubleshooting /testing/fixing this circuit as I'm at a bit of an impasse.
Thanks!
Quote from: brucer on December 27, 2016, 04:01:47 PM
I've been very tied up with holidays + family, but got back to troubleshooting this circuit last night. Unfortunately, I had little success.
Re: Govmnt_Lacky's concerns/suggestions around IC4, I confirmed that I don't have a short between Pins 13 and 14 with the chip removed (Yay!!).
Re: EBK's thoughts about flip/flopping voltages on pins 12 and 13 of IC4 by momentarily touching a 9v supply to a bent up pin 11:
- I tried once and was unsuccessful in flip/flopping pins 12 and 13 on my currently installed CD4013;
- I tried again and broke pin 11 off my currently installed CD4013 when bending it back into position (URGH!!);
- I installed the second CD4013 that I have on hand and it had the opposite pin 12 and 13 voltages from the first CD4013 that I tested.
Sooo ... not exactly the direct test of EBK's thoughts on flip/flopping pins 12 and 13, but suggestive that he's correct.
In any event, I still have clean signal only through the circuit and voltages are still the same as on the "Chip Set #2" page in my original post except that pins 12 and 13 of IC4 are now reversed.
I'd really appreciate it if anyone has some other thoughts on troubleshooting /testing/fixing this circuit as I'm at a bit of an impasse.
Thanks!
Welcome back! It's probably time to check out the clock circuitry, starting with pin 7 of IC6. Then pins 1, 2, and 3 of IC4. Then pins 2, 4, 6, 10, 12, and 15 of IC3. Looking for a clock signal in each of these places. Sorry about your broken IC pin. Again, I would encourage you to actually ignore the voltages on pins 12 and 13 of that chip. There are more meaningful tests you can perform on the pins that are actually connected to the rest of the circuit.
Thanks Eric. I appreciate your sticking with me.
Another newbie question though (sorry): will I know I have clock signal if I hear tone when using the audio probe of my testing rig (or do I test for it in some other way)?
I tried the audio probe on the board in (S) and out (R), just to make sure the probe was working (got tone on both). However, I get zero tone on pin 7 of IC6. In fact, the audio probe gives me no signal on any pin of IC6, except a sound like waves washing rhythmically on a beach on pin 3.
Should have a varying voltage on pins 2, 3, and 7 of IC6.
If you dont, then go further back. You said your LED is blinking, so pin 14 of IC5 is presumably good. Check pin 10 of IC5. Don't know what you should expect to hear with audio probe in this non-audio part of the circuit (perhaps someone else knows if that would help). Your DMM should at least show some changing voltages.
Thanks Eric. I can confirm varying voltages on all the pins that you mentioned:
- pins 2, 3, and 7 of IC6
- pins 10 and 14 of IC5
- pins 1, 2, and 3 of IC4
- pins 2, 4, 6, 10, 12, and 15 of IC3
Great. I'll assume your clock circuit is still working, although check for varying voltage at pins 2 and 6 of IC2 just to make sure. Note: I'm making a huge assumption here. Merely having varying signals is not conclusive evidence of good clock signals. An oscilloscope measuring pins 2 and 6 would be ideal....
(Another hunch: Check to see if Q1 is seated firmly in its socket.)
Is your clean signal making it to pin 3 of IC2?
Do you have a signal at the base and emitter of Q1?
(Trying to debug more rationally here. :icon_wink:)
Thanks Eric. I appreciate your continued guidance.
Quote from: EBK on December 28, 2016, 01:03:19 PM
Great. I'll assume your clock circuit is still working, although check for varying voltage at pins 2 and 6 of IC2 just to make sure. Note: I'm making a huge assumption here. Merely having varying signals is not conclusive evidence of good clock signals. An oscilloscope measuring pins 2 and 6 would be ideal....
(Another hunch: Check to see if Q1 is seated firmly in its socket.)
Unfortunately, I don't have an oscilloscope (and I don't know how to use one :-[). If the settings/tests are fairly straightforward, then I may be able to beg some time on one from a science teacher friend. He says that he has some donated scopes in storage, but they haven't been used in a long time and may not be calibrated (not sure what that means .... :-[ :icon_frown:).
In the meantime, I've confirmed varying voltage at pins 2 and 6 of IC2 and that Q1 is seated firmly in its socket.
Quote from: EBK on December 28, 2016, 01:22:33 PM
Is your clean signal making it to pin 3 of IC2?
Do you have a signal at the base and emitter of Q1?
(Trying to debug more rationally here. :icon_wink:)
Also, my clean signal is making it to pin 3 of IC2, but
not to the base or emitter of Q1. Does that suggest that my MN3007 is bad?
Thanks again, Bruce.
QuoteAlso, my clean signal is making it to pin 3 of IC2, but not to the base or emitter of Q1. Does that suggest that my MN3007 is bad?
Not necessarily. It could be that your MN3007 is bad, but it could also (perhaps more likely) mean that your clock biasing is not correct.
I would suggest you go through the biasing steps carefully, but instead of just listening for flanging at the output, keep checking for a signal at the base of Q1. It is possible that your perceived problem biasing the circuit may have really been a problem with Q1 or something connected after it.
If no matter what you do, you can not get a signal at the base of Q1, then consider replacing the MN3007 and trying again.
Solved! Thanks so much for your help Eric. After replacing the MN3007 and Q1, then re-biasing I'm back to a working flanger! I'm going to give it a few days now before trying to box it up. Very happy to have got it back up and running for now though!
Quote from: brucer on December 31, 2016, 09:14:36 PM
Solved! Thanks so much for your help Eric. After replacing the MN3007 and Q1, then re-biasing I'm back to a working flanger! I'm going to give it a few days now before trying to box it up. Very happy to have got it back up and running for now though!
Yay! :icon_biggrin:
The remaining question is: what caused it to fail when you boxed it up the last time? I'm wondering about the DC jack.... Does it have a metal bushing?
Yes, the previous failure is definitely troubling. That has me a little nervous about reboxing. The DC jack when last boxed was plastic with a metal nut.
Quote from: brucer on January 01, 2017, 01:32:50 AM
Yes, the previous failure is definitely troubling. That has me a little nervous about reboxing. The DC jack when last boxed was plastic with a metal nut.
Plastic DC jack is good.
Some more thoughts on how to be extra cautious:
Double check your stomp switch continuity in both positions before you wire it up again. Also check for continuity between the terminals and the outside metal parts.
Double check your DC jack outputs with a power source, again before you wire it up again to make sure it works as you expect it to work. Were you using the
same power source for test rig and in box?
Consider wiring it up in the box, but removing it from the box before powering it up again to test (i.e., to get it all connected with the wire lengths you want).
Good tips Eric. Thanks for that. I'll follow it step-wise. Re power for testing rig and boxed effect: yes, both were powered by a Voodoo Lab ISO-5 9v outlet.