Howdy folks. So, this is my first madbean build and, since I've only built about 3 pedals, I'm still a good bit new at this.
FWIW, I'm posting this over on the BYOC forum as well. Maybe someone can help.
Anyway, here's my issue. I know it must be something basic, but I'm stumped. I get no sound in bypass, or when the pedal is on. Also, when the pedal is engaged, the LED doesn't light up or anything either.
I'm trying to use the Road Rage board so I can use a power supply, and haven't installed the battery adapter. I know that can't effect the bypass signal, but I'm throwing that out there as I'm sure, even when I get a bypass signal, that I'll get nothing when the pedal is actually on.
Anyway, here are pics. ANY help is appreciated.
(http://i4.photobucket.com/albums/y130/dan7_69/Rangemaster/IMG_5820.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/Rangemaster/IMG_5815.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/Rangemaster/IMG_5814.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/Rangemaster/IMG_5813.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/Rangemaster/IMG_5811.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/Rangemaster/IMG_5810.jpg)
First thing to do is measure the power readings to the Road rage board, and then from the road rage board to the Rangemaster. Also, you need C4 to be installed on the Road Rage board and I don't think you have it in there...
Jacob
Ok,
I'm an idiot.... must've had my in/out cords swapped.. I get a bypass sound now. However, no sound when the pedal is engaged. I get a loud POP when turning it on, but no sound and no LED.
C4 is installed on the road rage. I'm only missing C1, C6, and C2. It might be hard to see, but it's there.
I"ve used the road rage on 2 Tonebenders already, and I've wired it the same way, I believe. No issues with those.
Still need your voltages going into and out of the Road Rage...
Jacob
Just did a check. I'm getting about 9.4v coming off the road rage. Same reading when checking the 9v pad on the pcb.
9.4 or -9.4?
-9.4v
Can you please test continuity from the ground plane of your board to the star ground point in your wiring with the effect switched off and on? Also, some shots of the solder/trace side of the board might help.
No issues with continuity from the board ground to grounding point on either the center of the switch or sleeve of the input jack.
Bottom shots for your viewing pleasure.
(http://i4.photobucket.com/albums/y130/dan7_69/IMG_5829.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/IMG_5828.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/IMG_5826.jpg)
Looks like there might be a solder bridge to ground from the R3 pad closest to R1.
Quote from: mgwhit on October 12, 2011, 03:24:15 AM
Looks like there might be a solder bridge to ground from the R3 pad closest to R1.
It does look like that glob of solder is bridging to ground. It also looks like a few points on the row at the bottom are touching. Could be the pictures its hard to tell. You might wanna use a bit less solder and make sure its bonding with the pad making a solid connection, not balling up and sitting on top. The rest of the joints look pretty solid to me.
The pads that are touching in the upper right of that bottom photograph are fine -- they're all on the same trace.
You could have a bad joint. Before soldering up an etched board, it should be cleaned and buffed. I use a scotch brite pad and lightly scuff the board then I'll clean it with acetone. It really helps the solder melt onto the copper. I can tell from your joints that you are not getting good adhesion to the board. They should be like a Hershey kiss not a chocolate ball. :)
Josh
I'm not sure I follow you on the solder bridge to ground. I've attached a pic (sorry, can't upload pics here at work.....), and circled two "globs" where I'm thinking you may be referring to.
I was assuming that these the two pads within each circle were ok if they were touching, but maybe I'm wrong.
I had a hard time getting those four to solder without 2 of them touching. I do have a desoldering iron, and I'll try to re do the 4 of them.
Would that be something that would cause the LED to not light up, for the circuit to not work, and also for the pedal to "POP" when turned on? Sorry, just trying to learn why things are causing issues rather than just fixing them.
Thanks for the help thus far!
Quote from: gtr2 on October 12, 2011, 01:59:13 PM
You could have a bad joint. Before soldering up an etched board, it should be cleaned and buffed. I use a scotch brite pad and lightly scuff the board then I'll clean it with acetone. It really helps the solder melt onto the copper. I can tell from your joints that you are not getting good adhesion to the board. They should be like a Hershey kiss not a chocolate ball. :)
Josh
That's good to know. I have a few more etched boards that I'm wanting to work on this weekend, so I'll do this. This is my 3rd build on an etched board, and the others fired up the first time, so I never thought this was an issue. Is there anything that I can do, short of either starting over or buying a new board, to fix this one, if the joints are the cause?
Check continuity of the two joints in suspect. You should not have continuity between those two.
This isn't a complex circuit, you'll get it worked out. No need to start over :) Check out the possible solder bridge before going further.
Josh
You're correct about the pads within each circle touching each other -- that's fine. What I was trying to say is that it looks like the solder globs in the yellow circle might be bridging to the ground plane -- the massive area of copper that makes up most of the board.
I can't tell from the photo if it's really bridging -- it might just be a piece of the component lead sticking into view -- but you can tell by doing a continuity test or just close physical inspection.
The blob in the red circle could be touching the ground plane, too, but continuity to ground there wouldn't make the effect silent. (In fact, bypassing R2 and C3 might make it insanely loud!) Continuity from the yellow circle blob to ground, would, however, result in a completely silent effect, as the guitar signal would go straight to ground before it could be amplified by the transistor. Good luck!
Sweet. Thanks for the replies guys. I'll give all of this a shot tonight once I get home.
I seriously need to read up on how to troubleshoot these things before running the the boards here. I just have no clue (yet!) on what should have continuity, what shouldn't, etc.
Quote from: bamadan5 on October 12, 2011, 02:48:34 PM
I just have no clue (yet!) on what should have continuity, what shouldn't, etc.
The way you know is by using both the schematic and the layout. For example w/ the rangemaster here, all ground pads are gonna have continuity and same w/ the components connected to the voltage source. From the beginning, the In pad is gonna be connected to one side of C1 and also C2. If you look at the layout you should see what I mean. Your not gonna be able to measure continuity through a components (except for a low ohm resistor like 1 up to about 100 ohms). The other side of C1 connects to the base of the transistor, as well as R1 and R3. If you follow the schem you can see what should and shouldn't have continuity..make sense?
I agree with mgwhit, it looks like the joint in the yellow circle is touching the ground plane. That'd be a good place to check for continuity. I'd also clean up some of the other joints..You might need to use a little more pressure with the iron to achieve better heat transfer. You wanna make sure your applying heat to the pad and the lead.
Ok. Update. Slightly good news.
I get a VERY faint sputtery sound with the volume turned all the way up. The pedal still pops LOUDLY when turned on. I've rotated the transistor around 3 times now, and even tried another. The current position is correct, per the datasheet, and I also get zero sound in the other two positions.
I reflowed all joints, and also corrected a few to work better. There is still one "glob" and after about 5 solder/desolder attempts, I don't believe it can be fixed. Its not touchin the ground pad, I checked.
Anyway, more pics below. Any further thoughts are appreciated. I'm going to work on a Neutrino project while I lay this one to the side. It's blowing my mind.
(http://i4.photobucket.com/albums/y130/dan7_69/IMG_5839.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/IMG_5838.jpg)
(http://i4.photobucket.com/albums/y130/dan7_69/IMG_5837.jpg)
Looks much better!! There's about 3 joints that connect to ground (R1, R2 and the other is the ground pad) that look like they need to be heated a bit more. When your ready to give it another chance try that. :)
You're a psychic. I hit the 3 pads you mentioned and it fired right up!
Only thing now is the LED isn't lighting, so I'm guessing I just got the polarity reversed. I should be able to fix that, I hope. I swore I check it 10 times, but i must be wrong.
If the polarity has been reversed it might have been blown. Also, if you didn't use a current limiting resistor (commonly at 4.7K) in series with the resistor that will blow it as well. If you have a spare try using that.
Glad it's working! It's frustrating I know, I've debugged a very large number of circuits. I have only had one beat me (and maybe another I'm currently working on will also beat me, though I don't think it's my fault...).
Jacob
Well, it appears I spoke to soon.
Now we have sound, and it works, but only the last 10-20% of the pot is actual "boost". Anything lower than about 3 o'clock on the pot is less than unity. With the pot at max, strumming hard on one chord causes the pedal to "flub" and it barely produces any volume for a few seconds after that.
That sounds like a bad bias... Is there a trim pot on the board?
It also sounds like you could have a problem with your transistor - are you certain of it's orientation?
Jacob
No trimpot on this board. I just again turned and reoriented the transistor to every possible position as well as 2 other OC44s that I have all with the same results. No idea where to go from here.
This just hit me... I'm wondering if there's something weird with the pinouts of the OC-44 that I have. maybe i need to cross a leg or something?
Anyway I can tell. I was looking at a random OC44 datasheet, but it might not fit for this one?
I got these OC44s from Mammoth a few months back. Markings on the package are "GT-OC44." Markings on the transistor itself are: NJS1045 OC44
Is there any other way to check what the C,B,E are? Anyone know off hand what they are for these specific trannies?
Other thought, is the fact that I'm getting -9.4v an issue? Is the .4 causing an issue?
Well, the first place I'd begin at this point is back at the beginning.
Double check that all your parts are the right orientation, the right value, and that you are getting -9ishV at the power in to the board and 0V on the GND connection. Getting voltages at each transistor leg is helpful also.
Jacob