Very low effect volume: short to ground?

Frequent questions about dead or faulty pedals. Whether you repair, mod or build pedals, debugging is important. Threads about general debugging problems irrespective of the circuit involved...
User avatar
rocklander
Old Solderhand
Information
Posts: 2890
Joined: 18 Apr 2008, 11:33
my favorite amplifier: my jansen bassman 50
Completed builds: rebote 2.5; supreaux; odie; heartthrob tremolo; ross phaser; dr. boogey; thor; baja black toast; slow gear attack, rebote, tri-vibe, small clone, little angel, magnus modulus, echo base, hex fuzz, big muff, 22/7.
Location: Rotorua, New Zealand
Has thanked: 1388 times
Been thanked: 229 times
Contact:

Post by rocklander »

980R is close enough to 1K to make me suspicions of the 1K resistor that is in parallel with the 10uF cap.
check that there is no bridged solder at the transistor side of that... maybe even pull one leg out for now, and see if the 980R is still there?
world's greatest tautologist ...in the world
Ronsonic wrote:...the lower the stakes the more vicious the combat.

User avatar
supernaut
Information
Posts: 17
Joined: 29 Jul 2009, 01:09

Post by supernaut »

Okay, I'll pull it out. But what would it be bridged to that it shouldnt be? It's meant to be connected to ground isnt it?

User avatar
rocklander
Old Solderhand
Information
Posts: 2890
Joined: 18 Apr 2008, 11:33
my favorite amplifier: my jansen bassman 50
Completed builds: rebote 2.5; supreaux; odie; heartthrob tremolo; ross phaser; dr. boogey; thor; baja black toast; slow gear attack, rebote, tri-vibe, small clone, little angel, magnus modulus, echo base, hex fuzz, big muff, 22/7.
Location: Rotorua, New Zealand
Has thanked: 1388 times
Been thanked: 229 times
Contact:

Post by rocklander »

supernaut wrote:Okay, I'll pull it out. But what would it be bridged to that it shouldnt be? It's meant to be connected to ground isnt it?
yup.. i'm wondering if it is somehow bridged to the input, before the 0.022uf cap?,, but like I said, I'm a n00b.. would be easier to troubleshoot if it was in front of me
:hmmm:
world's greatest tautologist ...in the world
Ronsonic wrote:...the lower the stakes the more vicious the combat.

User avatar
supernaut
Information
Posts: 17
Joined: 29 Jul 2009, 01:09

Post by supernaut »

You know, you might be right. I just noticed the input wire bridges two strips on the stripboard. It's a long shot because its only one strand and isnt all that secure, but I'll resolder the wire and see what happens.

User avatar
modman
a d m i n
Information
Posts: 4617
Joined: 19 Jun 2007, 16:57
Has thanked: 3478 times
Been thanked: 742 times

Post by modman »

supernaut wrote:You know, you might be right. I just noticed the input wire bridges two strips on the stripboard. It's a long shot because its only one strand and isnt all that secure, but I'll resolder the wire and see what happens.
Again: you don't need to heat your iron if you measure infinite resistance.
rocklander wrote:would be easier to troubleshoot if it was in front of me :hmmm:
In fact online troubleshooting is virtually impossible, you can never see what is going on. Still I got real intent on setting up a sort of Troubleshooting routine: first check this, then that, and so on. Anybody with a circuit to debug would be asked to run through that routine first, before posting his problems. Then that checklist could be expanded with the answer found.

Sometimes it will be silly, something you never thought of, like removing the copper scrapings from your stipboard and checking for contiuity after doing the cuts and before you would start soldering. :wink:
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

User avatar
supernaut
Information
Posts: 17
Joined: 29 Jul 2009, 01:09

Post by supernaut »

It's fixed. :applause: Rocklander was right. That tiny strand of wire that barely touched the adjacent strip was enough to send the input signal to ground via the resistor. A simple careful re-soldering later and it works fine. From now on I shall invest in a decent magnifying glass. Sounds great too, and really reacts to my picking technique. Which is exactly what I wanted. I just want to say thanks to everyone who helped. You guys are awesome. It can be hard to find a decent community in most forums, but I am definitely becoming a regular of this forum and will help other guys where I can.

User avatar
modman
a d m i n
Information
Posts: 4617
Joined: 19 Jun 2007, 16:57
Has thanked: 3478 times
Been thanked: 742 times

Post by modman »

supernaut wrote:It's fixed. :applause: Rocklander was right. That tiny strand of wire that barely touched the adjacent strip was enough to send the input signal to ground via the resistor.
Terrific! That's is why you had very low volume, and not just no sound at all.
Closing this thread and filing it in the FAQ under a more descriptive name.

Thanks everybody!
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

Locked