First Veroboard Project Acting Strangely - very quiet and intermittent output

[JagFan]

Hi all

New here so firstly thanks for reading.

I've built loads of PCB projects over the last few years (mostly from pedalparts/ Fuzzdog) and have had a 100% success rate so I thought I'd graduate up to a fun veroboard project:

https://www.bitsbox.co.uk/index.php?main_page=product_info&products_id=2033

I built it, triple checked the locations of all the parts, went to plug it in and....nothing. Well sometimes nothing. Sometimes if I turn all the pots up full I get some quiet output with nowhere near as much gain as you'd expect from a dimed Muff. I haven't wired up a footswitch so the input and output are directly attached to the circuit.

I'm sure this has been posted a million times before but I'd really appreciate some advice on how to go about trouble shooting what the issue might be. Where would you start and how would you test it?

I have a multimeter and a decent enough grounding in electronics from my degree/ hobby but need help from the experts!

Thanks
JF

[cab42]

First of all, welcome.

On the front page there is a link to the Debugging - What to do if it doesn't work thread: https://www.diystompboxes.com/smfforum/index.php?topic=29816.0

Pictures of front and back of board are also helpful.

A audio probe is a great device for finding out where the signal stops. You can easily build one yourself.

One thing I always do, when a vero build does not work, is taking a sharp knife and run it through the gap between the rows. Often this solves the problems if they are caused by a tiny solder bridge.

Also try to reflow your solder joints.

[11-90-an]

First of all... welcome to the forum...

^^^what he said.

Pictures are very needed. Please... 

[willienillie]

Bitsbox says the kit comes with BC550C transistors, which have a CBE pinout (which may vary by manufacturer).  The vero layout is for EBC pinout transistors.  Did you reverse them?

[JagFan]

Wow, thanks everyone! Some excellent tips already

I will take some photos this evening and post them.

Bitsbox says the kit comes with BC550C transistors, which have a CBE pinout (which may vary by manufacturer).  The vero layout is for EBC pinout transistors.  Did you reverse them?

No, I didn't. That may well be it! I will try the audio probe as well (can't hurt to learn how that works too).

[JagFan]

Hi all - pictures below. More practice required for neat solder joints I know but I've gone through with a multimeter and don't believe there are any shorts between strips.

https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/IMG_0114_1_.JPG.html
https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/IMG_0113_1_.JPG.html
https://www.aronnelson.com/gallery/main.php/v/Schematics-etc/IMG_0115_1_.JPG.html










I just checked and the transistors are BC550C and so should have been reversed. Hopefully just flipping them round will do the trick but there may well be something else I've missed that the eagle eyed experts may spot.

Any tips on how to delsolder a transistor without frying it? I have braid and a sucker pump.

[duck_arse]

I have questions. please tell me you have metered ALL those resistors before you soldered them in. those tiny brown ones - what are the colour bands on the 33k's please? and that one top right corner, what colours?

also, is the black wire to the right hand jack broken off the lug, cause that will put a crimp on your day?

do you have any spare transistors? if so, it might be quicker easier less frustration if you snip the transistor leads topside, and turf those trannies. they will still be good, if you want to try desoldering them. but yo'd have to really want to tangle w/ the desolder braid. then heat the leg and push or pull it out, leaving clean hole and undamaged track. then plonk in yer new transistors, reversed so as to match your datasheet, which you have handy as a reference.

also, welcome to the forum.

[11-90-an]

Or place sockets next time so swapping will be easier...

[kraal]

Hi all - pictures below. More practice required for neat solder joints I know but I've gone through with a multimeter and don't believe there are any shorts between strips.

I would re-check these ones.

[JagFan]

Wow - this place is amazing! Thanks so much everyone!

I have questions. please tell me you have metered ALL those resistors before you soldered them in. those tiny brown ones - what are the colour bands on the 33k's please? and that one top right corner, what colours?

also, is the black wire to the right hand jack broken off the lug, cause that will put a crimp on your day?

do you have any spare transistors? if so, it might be quicker easier less frustration if you snip the transistor leads topside, and turf those trannies. they will still be good, if you want to try desoldering them. but yo'd have to really want to tangle w/ the desolder braid. then heat the leg and push or pull it out, leaving clean hole and undamaged track. then plonk in yer new transistors, reversed so as to match your datasheet, which you have handy as a reference.

also, welcome to the forum.

Yes, I metered all of them and all were correct values according to the parts list and (i think) placed correctly. The colour bands on the resistor to the top right look like Red-Black-Black-Gold but it's quite difficult to tell, I need some better light and a magnifying glass I think!

The black wire has indeed come off - that's literally just happened as i moved the circuit around to take the photo. Was attached for sure when I've tested it previously.

Unfortunately I don't have any spare transistors. Might just be easier to order some new ones (and some sockets as 11-90-an suggests) than struggle with the existing ones.

Hi all - pictures below. More practice required for neat solder joints I know but I've gone through with a multimeter and don't believe there are any shorts between strips.

I would re-check these ones.

Thanks so much - I will go through them with a fine toothed comb later today. I tried re-flowing all the solder before posting on here to see if that was the problemand it looks like I may have actually made it worse! 

[JagFan]

I've flipped the transistors around, reattached the ground lug on the jack and gone around the board with a sharp knife making sure that there aren't any connections between strips and it's much much closer.

There's now output through the circuit and it's a nice fuzzy tone. Thanks for your help everyone!

The next challenge for those kind enough to keep helping though is that the output is lower than unity gain even with all the pots maxed. Also the tone pot seems to be acting more as a distortion/ volume control when you turn it down.

Any ideas? It feels like I'm so close but so far.

Thanks!

[willienillie]

I think some of your cuts are in the wrong places.

[JagFan]

I think some of your cuts are in the wrong places.

That's something I wasn't sure about when I was doing it. Should the cut locations in the bottom diagram be located as if you were looking at the component side or the solder side?

[11-90-an]

It should be as if you were looking at the component side...

The problem with most vero layouts is that they don't show what you should see when you FLIP the board around..(which is, the solder side...)

[cab42]

I think willie is right! Well spotted!

In the diagram the cuts are placed as you would see them if the board was transparent. That means you will have to mirror the positions when you flip the board.

I have done the same thing quite a few times. Luckily its often an easy fix. Solder a piece of component lead across the cut on the solder side and make the new cuts with a sharp drill.

When there are lots of scattered trace cuts, I often mark the cuts on the component side with a permanent marker (sharpie?). This way I can check the position on the solder side by inserting a component lead in the hole if I'm in doubt.  Another trick I use is to count the position relative to other cuts as a check. (e.g. this cut should be in row 8, column 5 but it should also be two rows below, and three columns to left of another cut). Check twice, cut once. However, I do manage to get it wrong sometimes anyway 

I do the the same thing when placing components, both absolute and relative positions. Marking the cuts on the components side also helps in this.

[JagFan]

I think willie is right! Well spotted!

In the diagram the cuts are placed as you would see them if the board was transparent. That means you will have to mirror the positions when you flip the board.

I have done the same thing quite a few times. Luckily its often an easy fix. Solder a piece of component lead across the cut on the solder side and make the new cuts with a sharp drill.

When there are lots of scattered trace cuts, I often mark the cuts on the component side with a permanent marker (sharpie?). This way I can check the position on the solder side by inserting a component lead in the hole if I'm in doubt.  Another trick I use is to count the position relative to other cuts as a check. (e.g. this cut should be in row 8, column 5 but it should also be two rows below, and three columns to left of another cut). Check twice, cut once. However, I do manage to get it wrong sometimes anyway 

I do the the same thing when placing components, both absolute and relative positions. Marking the cuts on the components side also helps in this.

It should be as if you were looking at the component side...

The problem with most vero layouts is that they don't show what you should see when you FLIP the board around..(which is, the solder side...)

That did it! The pedal is now up and running and sounding great!

I've learned a lot from this experience but definitely couldn't have done it without all your help. Thanks again!

JF

[r080]

I am really new to vero, but after some reading, here is what I found works for me:

On the component side, mark all the holes for links lightly with a black sharpie. Then, use a red sharpie and more pressure to mark all the cuts. Turn it over and look at it from a slight angle. The red marks should be visible in the holes from the backside. Of course, to be sure, use cab42's method of putting a lead through the top.

I also found it helpful to put a bright sharpie mark on the top left corner of my printed layout, and a corresponding mark on the top left of the board - helpful, but still not 100% effective for me.

[duck_arse]

good work on the fixxe, but you're not off the hook yet. we now want you to do voltage measures on all your transistor pins, see what we can learn from that.

[JagFan]

Haha! I could really grow to like this place, everyone seems to go the extra mile for people!

Q1, Q2 & Q3 all measured the same:
C: 4V
B: 0.63V
E: 0.04V

Q4
C: 4.6V
B: 1.6V
E: 1.1V

The pedal sounds good so I'm guessing these are right but I have no idea what's normal or what to expect!

[jfrabat]

If it sounds good, IT'S PERFECT!  LOL!

People here in my experience DO go the extra mile!  That is why I love this place.  With the help of a bunch of people here we managed to retrace and find all the errors of a circuit printed in a 1985 magazine article!  Could have NEVER done that by myself (especially considering there were A LOT of errors in the article!).