SOLVED Cobalt Drive problems…..SOLVED……..FINALLY!

[Jeff C]

New member here and also new to building pedals, as you will shortly see. I previously built a BYOC Reverb pedal kit successfully and it sounds great. I’ve also built from scratch a Strat, a Tele, a 59 LP, and an LP Junior. So, I wanted a blues driver pedal and thought I’d take a whack at the Cobalt Drive from PedalPCB. The directions are not as detailed as in a kit so I’ve had some difficulty. Clearly in over my head. I managed to procure the parts from the list (not without trial and error on my part) from Tayda. I mistakenly bought a switch without solder lugs so after consulting a patient, helpful friend, bought a daughter board and did my best to figure out how to marry the two - having no skills whatsoever in electronics. History major. I have managed to assemble it but I get nothing from it except static pops when I plug it in. Bypass doesn’t work. No idea what I’ve done wrong but I suspect it revolves around needing to do more with the daughter board on the switch. But what do I know? Here’s a couple of pics (the power jack is not there but I did connect it to test). And I haven’t installed the LED yet. Any and all suggestions are eagerly welcomed. You may recomemd I should just start over but I hope not….. Thank you!

 

[Jeff C]

Consider this one a practice run for the next build.

My main concern at this point is collateral damage. The board has suffered enough already. If we continue to touch-up solder joints & replace parts, there's a high risk of lifted pads. Sure, they can be repaired, but is it worth the effort of finding and fixing every last one?

If you don't already have a CCTT (Cheap Chinese Transistor Tester), then you would be well advised to get one. Pretty essential when building pedals containing FETs or Germanium transistors. They're around $20 on eBay. At least they were a couple of years ago when the dollar was worth something.

I don't know what kind of phone you have, but if you have a smart phone built in this century it will have a camera capable of much higher resolution than 640x480. Otherwise, there are pocket digital cameras for under $100.

Al lastly, when reporting DMM readings, report every digit. Sometimes it's that last 10mV we're interested in.

Good luck on the next build!

Thanks, Chuck!

 

[Jeff C]

Well, as the old guy in Monty Python and the Holy Grail said , "I'm not dead yet! I feel haaaapppy!" It works now. If that's all you need to know, don't read on. If you want to know how it happened, here goes:
I received the replacement Q5 transistor, put it in and it's voltage readings matched Q6 nicely. I also installed a new D100 diode.....correctly this time. But.......I still got no audio out. I didn't check all the other audio points and was about to give up entirely when I thought, "hell, I have a couple more IC's (TL 071) and that dang thing has been giving inconsistent readings too, so may as well pull that sucker. And while I'm at it, if I can get it out successfully, THIS TIME I'll put a socket in first." The replacement operation was long and painful (touched my index finger tip with the iron) but finally a success and readings looked good on the voltage. So, I just bypassed the usual audio probe testing and plugged that sucker in hoping for a miracle.......and voila! Audio out. All 3 pots work correctly and volume is great. I can't believe it. It would be awesome to end this thread on #420 but I got close. But in the end it WASN'T the salmon mousse!

Many thanks to all, especially you patient and regular contributors. And now I have a small confession to make re the IC, and why I decided to replace it. It was not a sin of commission, but one of omission because well, I just don't know much. You may recall how I demonstrated that lack of knowledge early in this thread. (I won't call it stupidity because, well, a stupid person just can't learn; nor will I call it ignorance because, well, an ignorant person just WON'T learn). You noted I had the D100 diode installed backwards. And then you suggested correctly that I had my input jack also wired incorrectly. But still I failed. So, here's my confession. I kept going upstairs and downstairs to work on this (from my music room to the basement workshop) and got tired of that, so I thought, I'll just stick to the music room but I'm tired of being on the floor to connect it to my pedal board power supply. So, what the hell, just pull that power supply power cord and plug THAT into my pedal so I can work at my desk. Of course, I had forgotten that my power supply doesn't just send 9v across it's 10 or so sockets, but has a couple reserved for 12 and 18 volts. So, for one session, I was running 18 volts through my pedal. Of course none of you knew that. And I didn't tell you because after I discovered it, I went back to a 9v power cord and got 9v readings on the PCB so I thought everything was ok. Doh! But no doubt, I must have fried something in the IC (a little internet research confirmed my suspicions). Of course, it wasn't just the IC because before I fried it, it still wasn't working. My guess is that I damaged the Q5 when installing it and the transistors were the only other things I was working on...... I suppose the aggressive alcohol scrubbing may also have helped. In any case, thanks again. Rock on!

 

[BuddytheReow]

The harsh reality is that we learn, or at least SHOULD learn, from our own mistakes. If you decide to make this board again I'll put money on it that it will fire up the first time! Happy you got it working. You're officially a DIY pedal maker now.

 

[EGRENIER]

Well done Sir…

Think of what you learned in this process and enjoy the new knowledge… now go build another one

 

[Chuck D. Bones]

Good to see you didn't give up and got it working!

I think this is a new record for highest page count troubleshooting effort.

18V would not have hurt that board. It might not have worked right, but there would have been no damage. If some parts were broken, there was another cause.

Some friendly advice:
Giving us all of the information up front or as it develops would have been helpful. You may not think a piece of info is relevant, but it just might be.
Save yourself some time and buy extra parts. You'll need them sooner or later and many vendors offer quantity discounts.
Take better pictures.
[I edited out one paragraph, it was intended for someone else troubleshooting a BD-2]

 

[Jeff C]

Good to see you didn't give up and got it working!

I think this is a new record for highest page count troubleshooting effort.

18V would not have hurt that board. It might not have worked right, but there would have been no damage. If some parts were broken, there was another cause.

Some friendly advice:
Giving us all of the information up front or as it develops would have been helpful. You may not think a piece of info is relevant, but it just might be.
Save yourself some time and buy extra parts. You'll need them sooner or later and many vendors offer quantity discounts.
Take better pictures.
[I edited out one paragraph, it was intended for someone else troubleshooting a BD-2]

And for you wankers out there, try cutting back on the memes, please. We have Breakroom for that sort of stuff.

Thanks, guys!

 

[EGRENIER]

And for you wankers out there, try cutting back on the memes, please. We have Breakroom for that sort of stuff.

I don’t get it… in the entire thread there is only one meme before the resolution.

 

[Chuck D. Bones]

I must have been hallucinating them because it's not possible for people to go back and edit them out of their posts.

 

[Mcknib]

Congrats on getting it going

You're not hallucinating @Chuck D. Bones I did edit out 3 pics two in the same comment when you came in to help

I've been away at my sister's so just back today anyway point taken no more memes especially if it's a long drawn out affair it just adds congestion

 

[fig]

Well done sirs. As promised on page…er….17! a $50 PedalPCB gift code is heading toward you..catch it or DUCK!

 

[Jeff C]

 

[Jeff C]

Your board is gonna have PTSD any time it sees an iron. Good job not giving up, I can cancel the BD-2 order now!

 

[Chuck D. Bones]

Any chance you plan on marking this one SOLVED?

 

[Jeff C]

Ah, didn’t realize I needed to do that…….although the solution remains a tad mysterious….. Do I just post SOLVED, or is there some box to click on? Can’t seem to find one……….

 

[giovanni]

At the top of the thread you can edit the whole thread, which simply lets you add the “solved” prefix.
Also I haven’t been following this thread for a few days and I’m very happy to hear that you got it working! That’s a fantastic satisfaction when you get to that point especially after all the troubleshooting. So congratulations for that! I hope this experience hasn’t turned you off to building pedals. It can only improve from here on! And we are here to help, as much as we can. Cheers!

 

[Jeff C]

Thanks!

 

[MichaelW]

@Jeff C Go to your first original post and click "Edit".

Then select the "Prefix" drop down list and select "Solved" (see attached pic) This marks the thread as Solved with a badge so everyone knows we're done here. Congrats on finally getting your pedal working btw, that was some herculean persistence

 

[Jeff C]

Tks! Done!

 

[benny_profane]

Can wait for the book deal for this thread.

 

[Coda]

Can wait for the book deal for this thread.

…and the film series, which will rival Peter Jackson’s Middle Earth for scope, length, and hobbits…