Build Your Own Clone Message Board

hello i just finished my pedal and the only thing that seems to work is the foot switches and leds. Not sure about the transformers they seem to do something that might be right but since I m not getting any signal i can not tell for sure. With input cable plugged into input a or b wich as i understand would be the right side i cn not get signal through in any configuration. So hopefully someone can give me some pointers on what to look for. I have rechecked all instructions and reflowed all solder connections and i hve same results. I have taken pictures and hopefully you guys can help out. Thanks in advance. Oh by the way i am not exactly an electrical engineer so feel free to talk down to me, that way i might understand[url][/ http://m1258.photobucket.com/albumview/ ... 1.jpg.html ] http://m1258.photobucket.com/albumview/ ... 8.jpg.html http://m1258.photobucket.com/albumview/ ... 1.jpg.html http://m1258.photobucket.com/albumview/ ... 7.jpg.html http://m1258.photobucket.com/albumview/ ... 1.jpg.html http://m1258.photobucket.com/albumview/ ... 2.jpg.html

Your photos are way too small. We need large pix (but not so large they need to be seen on a 60" flat screen) that show a LOT of detail. It's got to be as if we have the build right in front of us. The photos need to be crystal clear too. Don't post pix that are the least bit out of focus. The more detail you can show us the better.

Let me know if this is what you need. I tried a diffrent camera. Thanks http://m1258.photobucket.com/albumview/ ... l?newest=1

Still looking for help with my hundred dollar paper weight. Any suggestions would be greatly appreciatsd. Thanks

Still too small.

Your work looks fairly neat, but Stephen is correct to say that the images are still too small to see potential problems with your build.

I'd recommend making sure they are about 500-600 pixels at the longer dimension; that seems to be the sweet spot for size. One other thing you can do to make it easier is use the IMG tag that Photobucket provides and drop them into your post—that way everyone can see them without leaving the BYOC forum.

Good luck. Don't give up! Once you get the photos up and running, one of the super sharp people here will very likely find your problem.

hope this works if not keep the info coming it gives me new things to try thanks

Those photos look better, and hopefully someone more knowledgeable than I can help you better now.

Your photos are a little better they still don't show the kind of detail we need to see. Take a look at the pix in this thread...

viewtopic.php?f=51&t=35727

Notice how you can see each solder joint clearly. This makes it much easier for us to tell if you have a problem with the quality of your soldering. We need to see the shape of the solder joint and whether or not the solder has a smooth shiny look to it like chrome or if it is dull and/or porous looking.

Hopefully these will cut it.

You have the MAX1044 (IC5) in the wrong place. You have it flip-flopped with IC3. Hopefully you didn't fry both chips.

Thanks Stephen I did not even realize any of the ic's were diffrent. Now I see the parts list warned me. So now I switched them and chanel a works as long as the transformer is off, and channel b out does not work. Signal gets through but not at full volume. So I am going to order two new ic's and i will let you know if that fixes it. Thanks again for giving me some direction to go in I really apreciate it.

Install the 1044 in it's correct socket and leave the IC3 socket empty. Power up the pedal and take voltage readings at pin 8 of each op-amp (IC1, 2 & 3). If you have voltage at these locations you won't need to replace the 1044 chip.

OK so i tested dc voltage on ic 1,2, and 3 and i get between 7.5 and 8.3 volts. I did this by probing the last two legs on the ics i hope that is what you were looking for. I then tried it out with old and then brand new ics with same results. I now get signal from channel a to channel a just fine however channel b out put has a very quiet signal that is very crackly. Also the transformers make horible noise unless in the off position. Hopefully you guys have other thoughts or places for me to stick my multimeter. Thanks in advance. Dave

Here's a tutorial on taking voltage readings: http://www.ladyada.net/learn/multimeter/continuity.html

And here is the pinout of a DIP IC for reference:

Take and report voltages from each pin of each IC please.

Can i use the housing as ground or should i fing ground some other place
After I posted this I tried it and the case did not seem to work so i used the negative leg on the power jack and I get 8.72v at all three ics 8th pin. Thanks

Yes, the negative terminal of the DC jack is a good place for the black probe. Please report voltages from every pin of every chip, not just pin 8. And there are 4 chips.

I took these readings with the transformers both in the off position, the red and green led on, and no cables in 1/4" jacks.
Ic1 #1-.3mv #2-.3mv #3-.5mv, #4-8.3v, #5-2.2mv, #6-.5mv, #7-.5mv, #8-8.8v
Ic2 #1-6.9v, #2-.38v, #3-95mv, #4-8.3v, #5-.3mv, #6-.7v, #7-.8v, #8-8.72v
Ic3 #1-1v, #2-1.5v, #3-.78v, #4-8.7v, #5-.7v, #6-1.7v, #7-.7v, #8-8.1v
Max1044 #1-8.71v, #2-4.3v, #3-0v, #4-4v, #5-8.3v, #6-4v, #7-6.5v, #8-8.72v

Hope these help and thanks again.

The MAX1044 takes the 9V from the battery and turns it into +9 and -9 volt rails to feed the supply pins of the other ICs. The most important pins on the MAX1044 are pins 5 (-9 out) and 8 (+9 out).

These pins won't be at exactly 9V and they aren't but you don't seem to have indicated which readings are plus and which minus. Using - as a separator in your list for all the voltages is a bit confusing. To make your measurements if you have a digital meter keep your meters black minus probe on the circuit ground and move only the red plus probe. When you do that all voltages positive of ground read as plus voltages and all negatives as minus voltages. If you have an analogue meter with a needle you will have to swap the probes around and put the red plus probe on the ground to read the negative voltages but you should write them down as minus voltages. Write the positive readings as plus.

So all the -9 pins on the other ICs (pins 4) should be connected to pin 5 of the MAX1044 and read the same voltage -8.3V. Pins 4 on IC1 and IC2 do but you show 8.7 on pin 4 of IC3? Suggest you re-measure that one.

Likewise pins 8 of IC1,2 & 3 should show the same voltage as pin 8 of the MAX1044 ... 8.72V and only pin 8 of IC2 does, so check pins 8 of IC1 and IC3. Maybe your meter is a bit odd or your probes aren't contacting properly.

All the other pins on iC1,2 & 3 should be pretty close to zero when the pedal is working normally and many are except for pin 1 of IC2 which appears to be at 6.9V (plus or minus ? in turn this will affect the voltages for IC3). Take a very close look (a magnifying glass and a bright light really help) at the tracks connecting to IC2 for shorts or poor joints. If you cannot see anything remove the IC and measure all the pins on the socket. You should see the minus and plus supply voltages on pins 4 and 8 and close to 0V on all the others.

You might try swapping the IC for another and see if 6.9V remains on that pin or if it follows the IC you removed. If it follows the IC that IC is probably faulty.

Thank you Tark,

That all makes alott of sense, it was dumb of me not to note wich readings were negative. Also iI changed the battery in my meter and it is way more conistant. However I am still getting -6.9 v at ic2 pin #1 even when switching chips. I do get about zero when there is no chip at all, I have inspected as best I can and see no shorts or cold joints. All other readings are consistent with your previous post. Thanks again for helping me work through this.

OK - if you get -6.9 at pin1 of IC2 even when you switch chips but zero with no chip that means that pin1 is not shorted to the minus supply but there is a problem with the circuitry feeding the inputs of IC2 - pins 2 or 3.

If you plug a jack (an unconnected cable or just an unwired jack plug will do) into socket B does the voltage at pin 1 of IC2 change? Probably not because pin 7 of IC1 and pin 3 of IC2 seem to be about the same voltage and near zero. Pin 2 of IC2 seems a little off, I assume that is + 0.38 volts which it would have to be for the output to be minus. This is a little weird because that pin only has the feedback resistor from the output (R10) connected to it. Check your joints to that resistor. If you remove the chip does that resistor measure 10K between pins 1 and 2 on the chip socket?

Check the joints for R9 also.

With a jack in socket B that IC is pretty isolated from the circuit, apart from the power rails and ground the only connection to the rest of the pedal is through R11. Your problem almost certainly lies in that very limited area.

Thanks again Tark I really appreciate your feedback.
So I assume you mean output jack b, but i checked pin #1 of Ic2 with it plugged into b out and b in and it is essentialy the same except that when in the input b it is -6.8v. As far as pin #2 of Ic2 it is negative but very low usually about -.6mv, is that wrong? Also I dont see R10 on Stephens schematic. Is it the socket for Ic2? If it is I checked the ohms from pin #1 and #2 and got no connection. As for R9 it is not a cold joint it could possibly be starved but I can not see the side I originally soldered because it is under jack output A so i can only see it from the resistor side. Should I reflow this joint from this side? Thanks again

Scroll down to the bottom of this page and see the notes where the Router PCB is located. It's just below the photo.

viewtopic.php?f=9&t=4508&start=25

No I meant input B.

I am referring to the circuit schematic that is included in the current downloadable instructions. I was assuming that your IC numbers and measurements related to that too.

That shows a 10K resistor connected from pin1 to pin2 of IC2a

Apparently the scematic in the instructions is wrong and r2 and r10 are not in the actual build. Stephen mentions it in his sticky up above. I also took an ohms reading from the resistor side at r9 without actually touching the resistor only touching the contacts on the board and I get the .997 m wich is i assume what it should be. So i dont think it has a connection problem. Any othern things for me to check. Thanks