sound on bypass, but not when engaged......

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...
Locked
travisthedog
Posts: 5
Joined: 31 Mar 2012, 09:15

Post by travisthedog »

So I'm a relative noob to this building lark but have built a few "kits" but I have one at the mo which is really doing my head in!

It's a zvex super hardon clone so pretty basic, but when its in bypass the signal passes to the amp, but when its engaged, the led lights but there's no sound. There's power at the 9v socket, power at the board and no apparent shorts on the Vero, but, when switched on, no power at the switch. The 9v comes from the power in through the led and then through a 4k resistor to the footswitch. There is no power beyond the resistor (at the fs) when the switch is on, but there is when its off.

Any ideas?

User avatar
Seiche
Old Solderhand
Posts: 2590
Joined: 01 Nov 2010, 01:16
Location: Germany
Has thanked: 227 times
Been thanked: 185 times

Post by Seiche »

transistor in backwards?

what do you mean by saying "there is no power at the switch"?

travisthedog
Posts: 5
Joined: 31 Mar 2012, 09:15

Post by travisthedog »

Seiche wrote:transistor in backwards?

what do you mean by saying "there is no power at the switch"?
Transistor is ok.

I mean that (rightly or wrongly) I assume that in bypass the switch stops the power going to the circuit. So when engaged I lalso assumed that there would be a power reading on one of the pins of the 3dpt to send the power to the circuit. Like I said. There is power at the 3dpt when the switch is off

User avatar
Seiche
Old Solderhand
Posts: 2590
Joined: 01 Nov 2010, 01:16
Location: Germany
Has thanked: 227 times
Been thanked: 185 times

Post by Seiche »

travisthedog wrote:I mean that (rightly or wrongly) I assume that in bypass the switch stops the power going to the circuit.
no, there is power to the circuit as soon as you plug in the input jack in a standard wiring with a battery. The battery supplies power to the circuit not the switch.

Can you post pictures of the board? Which layout did you use?

travisthedog
Posts: 5
Joined: 31 Mar 2012, 09:15

Post by travisthedog »

I can't really post the schematic as I'd get into allsorts of trouble, but let me re assed with the guitar leads plugged in and report back.......

User avatar
Seiche
Old Solderhand
Posts: 2590
Joined: 01 Nov 2010, 01:16
Location: Germany
Has thanked: 227 times
Been thanked: 185 times

Post by Seiche »

:scratch: why would you get in trouble? And by schematic you probably mean layout, no? Because the schematic has been posted dozens of times here.

travisthedog
Posts: 5
Joined: 31 Mar 2012, 09:15

Post by travisthedog »

Only because it was bought from a company and I assumed there would be copyrights over their layout pictures that they send out with each kit?

User avatar
Seiche
Old Solderhand
Posts: 2590
Joined: 01 Nov 2010, 01:16
Location: Germany
Has thanked: 227 times
Been thanked: 185 times

Post by Seiche »

it's just an SHO. there's only so many ways you can arrange one transistor and a few components. Which company is the kit from?
Post pictures of the board and footswitch wiring then, they are your own copyright (because you own it and took the pictures).

otherwise no one will be able to help you if all you're providing is "it doesn't work".

User avatar
DrNomis
Old Solderhand
Posts: 6896
Joined: 16 Jul 2009, 05:56
my favorite amplifier

Self-Built Valve Amp Head :)

Completed builds

Dallas Arbiter Fuzz Face,Tone Bender Professional Mk 3,Tone Bender 3-Knob,Baja BK Butler Tube Driver,Baja Real Tube Overdrive,Roger Mayer Octavia,EH Soul Preacher,Tech 21 XXL Distortion,MFOS Weird Sound Generator.

Location

Darwin,Northern Territory Australia

Has thanked: 99 times
Been thanked: 267 times

Post by DrNomis »

Could be a faulty footswitch, this would also explain the "no sound when engaged" issue, I'm guessing that you used a 3PDT footswitch, if so, what you need to do is engage the effect without a battery installed, next set your multimeter to a low-ohms range and then check the contacts to see if you're getting continuity where you're supposed to, if it looks like you're getting open-circuits where there should be continuity, then replace the footswitch with a new one, sometimes those 3PDT footswitches end up with lose contacts if too much heat is applied while soldering, leading to faulty and unreliable contacts.... :thumbsup
Genius is not all about 99% perspiration, and 1% inspiration - sometimes the solution is staring you right in the face.-Frequencycentral.

User avatar
modman
a d m i n
Posts: 4607
Joined: 19 Jun 2007, 17:57
Has thanked: 3469 times
Been thanked: 727 times

Post by modman »

http://diy-fever.com/misc/audio-probe/
Seiche wrote::scratch: why would you get in trouble? And by schematic you probably mean layout, no? Because the schematic has been posted dozens of times here.
This git has gotten his kit from a website that is careful not to mention brand names... or organize a support forum. I suppose, let's not get into the trouble.... :mrgreen:
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal

Locked