PROBLEM: Crybaby From Hell WAH

[spartadrive_in]

I have a Dunlop Dimebag Crybaby from hell that will not "wah". When I engage the switch the only sound that I can get is the usual 'Heel-Down' sound no mater what position the foot pedal is in.

Clean sound does come through when the pedal is disengaged.

I checked the pot with my meter and it reads 100K and it DOES change value when rotated. (It's a Hot-Potz)

I also checked the FASEL Red inductor in there and I DO receive continuity.

What else could be the problem?
Any help is appreciated.

[Steve Conner]

The pot might change value when it's rotated, but does the pot rotate when the pedal is pushed? The gears might have fallen out of whack.

[spartadrive_in]

The gears were the first thing I checked and they are fine.

[EffectsGuru]

I have a question? Why not just send it in to dunlop.. I sell these and I own a bunch as well, their really fast at repairing and getting things back to you. I've sent a few in for customers a long time ago (switches), and I have sent in one myself... it took 2 weeks and they didn't charge me.. covered on the warranty...

That being said I understand if you like to fix things yourself... I have built 3 guitars, an amp, repaired tons of stuff, and I started building pedals recently... but honestly if a Dunlop pedal breaks... I'm just going to send it in under warranty, because they gladly fix it when it's their fault.

[spartadrive_in]

I have a question? Why not just send it in to dunlop.. I sell these and I own a bunch as well, their really fast at repairing and getting things back to you. I've sent a few in for customers a long time ago (switches), and I have sent in one myself... it took 2 weeks and they didn't charge me.. covered on the warranty...

That being said I understand if you like to fix things yourself... I have built 3 guitars, an amp, repaired tons of stuff, and I started building pedals recently... but honestly if a Dunlop pedal breaks... I'm just going to send it in under warranty, because they gladly fix it when it's their fault.

You're right, the fun part is doing it yourself. Most broken pedals someone acquires are usually not the original owner so warranty may not apply there.

[R.G.]

I have a Dunlop Dimebag Crybaby from hell that will not "wah". When I engage the switch the only sound that I can get is the usual 'Heel-Down' sound no mater what position the foot pedal is in.

Clean sound does come through when the pedal is disengaged.

I checked the pot with my meter and it reads 100K and it DOES change value when rotated. (It's a Hot-Potz)

I also checked the FASEL Red inductor in there and I DO receive continuity.

What else could be the problem?
Any help is appreciated.

The wah circuit is too simple to be much of an issue. Go read "The Technology of Wah pedals" at geofex.com and then dive in. I would start by measuring the DC voltage to ground of every pin of the two transistors in there. An NPN transistor - like those - can only work as an amplifier if the emitter is the lowest voltage, the base is 0.5 to 0.7V higher than the emitter, and the collector is from half a volt to many volts higher than the base.

While you're checking voltages, check to see that the battery/DC supply is getting through to the actual PCB.

A resistor only has current flowing through it if it has a different DC voltage at each end. And a resistor MUST have a voltage across it of V=IR always. A capacitor with the same DC voltage on each side must be viewed with suspicion. It is possible that the circuit puts the same DC on each side, but except in pure-AC circuits with no DC involved anywhere, that's unlikely.

An inductor can measure continuity, but be internally shorted; this is unlikely to about the seventh power in a wah inductor.

Last stop is wires. Do the wires connect where you think they do? None broken? None resoldered by the last genius to work in there?

[Steve Conner]

I have a little tale about Dunlop that may be relevant.

Once I went into my local music store and saw a box piled high with Dunlop Crybabies and JH-1s for £15 each. I asked what the deal was, and the clerk said that they were faulty customer returns, they found them lying in a storeroom and needed rid of them. So feeling lucky I bought two JH-1s.

One of them turned out to have a broken stomp switch, and the other had a dry joint on one of the wah pot terminals. I had them both fixed in an hour, kept the one whose tone I preferred, and sold the other one on Ebay for more than I paid for both of them. So yes, I like Dunlop's customer service.

[EffectsGuru]

Oh ok, I must have missed something I didn't know that he wasn't the original owner...