Please help me debug my Sparkle Boost - getting no sound!

[monkmiles]

Hello all...

So I just completed my first build and when I go to try it...nothing. Please help! As a newbie I don't know where to start. I'll provide as much detail, pics and what I've checked so far...

Firstly, I'm using a MarkM layout, etched/drilled pcb for a NTE458 Sparkle Boost. However, I'm using a j201, so I'm swapping two of the legs (yes, I did insulate them and I was able to bias between 4.5-5v). Below, I will post a pic of this layout and the wiring diagram I followed for the switches, jacks, etc. In addition to pics of my pedal.

When I power it up, the bypass signal will come through, but when I switch it on, I get nothing and not even the LED lights up.

I measured voltage at the j201 (4.5-5v), the +9v node and at the switch and all had power.

Here are a bunch of pics of my pedal: http://img97.imageshack.us/g/img0354u.jpg/

Here is the layout and wiring diagram I used:
Layout: http://www.aronnelson.com/gallery/main.php?g2_view=core.DownloadItem&g2_itemId=1855&g2_serialNumber=2
Wiring diagram: http://diystompboxes.com/beginner/circswleddc2.jpg

Can anyone provide specifics on what I can check? So disappointing after I "completed" my first build!

Thanks in advance!

[PRR]

> voltage at the j201 (4.5-5v)

That thing has three legs..... are you saying they are all 4.5V??

> don't know where to start.

Stuck near the top of the forum: DEBUGGING - What to do when it doesn't work

[mmaatt25]

Hi,

Check your wiring on your 3PDT switch, where's that yellow cable in the centre lug of the switch go?

Matt

[monkmiles]

Thanks for the replies guys.

That thing has three legs..... are you saying they are all 4.5V??

> don't know where to start.

Stuck near the top of the forum: DEBUGGING - What to do when it doesn't work

No, just the drain on the j201 has that measurement.

I've been reading that debugging thread and will look at it some more.

Check your wiring on your 3PDT switch, where's that yellow cable in the centre lug of the switch go?

That goes to the LED. Goes from the switch's center lug to a 10k resistor to the shorter leg of the LED.

[deadastronaut]

could be a ground problem.....make sure its grounded...on the board and switch jacks etc...

maybe!..good luck.

[monkmiles]

could be a ground problem.....make sure its grounded...on the board and switch jacks etc...

maybe!..good luck.

Very possible. I'll see if I can figure that out. Any recommended way to make sure everything is properly grounded? I'm measuring voltage and perhaps it just isn't properly grounded somwhere?

I should note I have not wired up the batter snap. I didn't think that would matter yet. Have just been using the power jack.

The wiring diagram I followed I linked to in my initial post.

[monkmiles]

whoops, ignore...double post from the post above

[stringsthings]

do you have a DMM? .... if not, you will need one eventually and they're not expensive .... if so, check each connection for continuity .... double check the polarity of the LED and the electrolytic caps .... 

... if you find yourself becoming frustrated, set the project aside ..... trouble-shooting requires a cool head .... and believe me, we've all been there .... i got back into the hobby a few months ago and fried a chip by being careless !  ..... so stay away from the frustration bug as much as possible .....

[monkmiles]

do you have a DMM? .... if not, you will need one eventually and they're not expensive .... if so, check each connection for continuity .... double check the polarity of the LED and the electrolytic caps .... 

... if you find yourself becoming frustrated, set the project aside ..... trouble-shooting requires a cool head .... and believe me, we've all been there .... i got back into the hobby a few months ago and fried a chip by being careless !  ..... so stay away from the frustration bug as much as possible .....

Yep, I do have a DMM. I've done some voltage checking and some continuity checking. I will do more though.

[PRR]

Now I remember this circuit. You say you got the 4.5V..... were you able to trim to 8V and below 3V and ended up at a nice 4.5V? Then the DC part of the circuit presumably works OK.

So check the AC/Audio path.

You know the buzz you get when you touch the tip of a live guitar cord?

Same if you stick a finger in a stomp box while plugged to an amp.

So finger your way through the circuit. Signal comes in at IN, through C1, through Q1, through C3, to R4 and top of Level pot, to wiper of level pot, to output jack.

You really should get buzz when you finger the output jack. If so, work backward toward IN. Past C3 you will need to have power to the circuit. Please use a 9V battery, it's safer for finger-poking diagnostic.

[stringsthings]

.....Please use a 9V battery, it's safer for finger-poking diagnostic. ....