Pedal Builders - do you have a particular sequence/method for trouble shooting?

DannyP

 

DannyP

BTW, I realise that some of the wires to the vol pot had snapped where they join the board due too excessive wiggling at the time of the photos. I remedied this and it still doesn't work. 

DannyP

http://i611.photobucket.com/albums/tt192/p1eces/chilly2.jpg

 

 

 

 

Misterg

It's difficult to make out the detail in the photos, but there appears to be a bit of a dodgy looking solder joint:

http://i255.photobucket.com/albums/hh143/werdnayarg/webstuf/chilly3_zpsc736535c.jpg

It's in a place that would kill your signal if it is dodgy.

If you can get nice, big, crisp photos, it'll be easier

Maxi

Just looking at the soldering ....

It looks like you may have cooked a couple of solder pads but Ive seen worse on working boards , obviously these pics show a board that cannot work as there are missing connections that you already admitted but your description of getting the thing to work by touching the underside could actually be a dry solder joint . Wire it up leave the back off ,I just use a continuity function on my multi meter to test the solder joints and ground paths to the metal box and traces between components . I just get a *beep* where connections are good . This kinda goes back to your original post with fault finding . It looks like a nice board to solve a pretty simple over sight... a perfect rite of passage project to get working . It just needs a slow and deliberate step by step circuit test but its a fairly basic layout ...component list is low ...I'd start with testing the solder joints with the meter via the connecting legs of the components but not through the body of components  . once thats confirmed as all good then your looking for a cooked component or even an off board fault .

DannyP

Cool, many thanks, I just need to find the time to go through all of this thoroughly.

DannyP

Just to bring all this to a rather unsatisfactory conclusion......

 

I opened it up again, I lift the board up a bit - it works.

I push it down a bit, it doesn't work. A difference of bout 10 degrees.

I got it so it wasn't working and checked all the connections, working through the schematic from last leg of last component to next leg of next component - all connections are good.

I decided it must be the wires that connect to the board that are at fault, given that tilting the board back and forth by 10degrees turns it on and off. With the effect not working, I checked continuity of 9v to board, ground to board, signal in to board, signal out to board, and all lugs of all pots to board - all connections are good - aaaargh!

 

By this time, while trying to run all tests while the effect was not working, I actually found it quite hard to wiggle the board to STOP it working.

I found a position where the effect would work and the enclosure lid could be closed. I stuffed foam all round it, screwed the lid on and it works, no matter how vigorously I shake it!

Like I say - an unsatisfactory conclusion as I'd have liked to have got to the bottom of the problem. Plus I don't have much trust in its long term reliability. But at least it works (and sounds fantastic).

 

Maxi

It should not be boxed at all in its current state .

Get all of it out of the box before you try solving this one ....trust me you'll find the fault a lot easier .

You'll be able to use eye's for starters .

The volume pot sounds like it might be a cause for further testing , you could just replace it . Ive had plenty of dodgy pots on my builds .

Another way you can test the continuity is to do what you have already been doing but this time use crock clips on your multi meter between the board and off board components and then start tilting the board as before but if the fault is the pot then you'll have to connect the clips between lugs 1 & 3 or 1& 2 and so on to see it as well as checking the lug soldering quality .

Another thing is just because your finger was brushing the underside of the board when it started working doesnt mean the fault is with the board . If you give a resistance a push it can change from open to closed circuit and that fault could be any where .

frankus

bendy board means a flaky connection somewhere doesn't it... I've had issues boxing stuff before and it's always been earthing problems.

Maxi

Yes in particular the earthing of my gain pot on my last board . 

Misterg

DannyP said:

I stuffed foam all round it, screwed the lid on and it works, no matter how vigorously I shake it!

Likely it will continue to work fine...










...until it really matters :-/

It's worth sticking with it if you like the pedal.

Maxi

Yeah I really feel for DannyP . Its gonna conk out again at some point . I'd be having the thing out of the box to find out exactly which wire causes the cut out otherwise its just gonna be sitting there saying "please throw me in the bin" ... 

DannyP

Yeah, Maxi, I know you're talking sense, and I will have to get it sorted properly to give me piece of mind. I make money from playing to paying punters so it's irresponsible of me to have something unreliable in the chain. I'm thinking of keeping my Marshall BB2 on the board for backup dirt, but it's not really a satisfactory state of affairs.

But, yeah it needs sorting properly.

Maxi

Truthfully I dont know but youve provided some pretty useful clues .

Im sure its just a gnats whisker away from being 100% working .

Try building something else and then go back to it later .

DannyP

Sad news. After a long struggle, my Chilli Biscuit was declared dead on the operating table yesterday evening.

For those of a nervous disposition, this post contains images that some forumites may find distressing.

 

 

 

 

 

 

 

 

 

http://i611.photobucket.com/albums/tt192/p1eces/20131205_144743.jpg

http://i611.photobucket.com/albums/tt192/p1eces/20131206_120424.jpg

 

It wasn't pretty towards the end. I stripped it back to the board testing stage to eliminate switch probs, resoldered all the pots with new wire and tested for continuity across every connection. I probed it from both ends and it always stopped working at the IC. Swapped out the IC for a spare, still didn't work. Checked power going to the IC and that was fine.

Even though I still haven't got a clue what's wrong, when I saw it lying there with all wires going in and out of it, I realised it was time to let it go. Sleep well sweet stomp. Fnup fnup.

 

Misterg

R.I.P. [*]






[*] Rest in parts box.