Pedal Problem

[JOHN FUZZY]

Yesterday i bought a used MXR JHM1 Fuzz Face anniversary and it looks brand new. The guy that sold me said he tried it the day before and it worked perfectly. But i connected it to some universal adapter (which i use and my other pedals are working) that was on 12V and the LED on adapter shutted off. I have signal and sound from the amp but when i press the pedal there is no sound, no LED on pedal, nothing. I put the adapter on 9V and again it dosen't work...I tried it with 9V battery, still no sound and the baterry heated up very fast. Did i destroy it? Wouldn't like that to happened, it's a cool pedal. Does it need a specific power suplier and will it work? Anybody had simillar problem?

 

[beaubrummels]

Specs say 9V. Not sure what damage could have happened by running 12V into it. I would have thought it would only draw 9V though 12V was available, but it could have damaged it.

Input Impedance 10kΩ
Output Impedance
Max Volume 2kΩ
Mid Volume 50kΩ
Max Output -6dB
VMax Gain 45dB
Current Draw 3.4mA
Power Requirement 9 volts DC

 

[superpete]

millivolts* work like a reservoir where the pedal draws what it needs, voltage is different. plugging a 12v power supply into a 9v pedal can fry it.

edit: i meant milliamps. so if a pedal is 9v 100mA, the power supply can have any amount of ma as long as it's over 100; the pedal will only draw what it needs. Voltage, however, needs to be correct or you risk damaging the pedal. That is to say, it won't only draw 9v from an 18v power supply, it will be hit with twice as much voltage and likely be damaged.

 

[CapoFirstFret]

Also I don’t know that pedal specifically but fuzz face style fuzzes (which I think that is?) often need center negative power instead of the regular center positive. Gonna need a tech for this one


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[JOHN FUZZY]

But what does it mean? Did I burn it and if i did can it be fixed?

 

[Hsb]

Kinda sounds like you killed it. Not sure what/if it could be repaired.

 

[Artie]

millivolts work like a reservoir where the pedal draws what it needs, voltage is different. plugging a 12v power supply into a 9v pedal can fry it.

I think you meant milliamps there. And yes, voltage is the "pressure" applied. Current is "drawn out" based on that pressure.

 

[GuitarStv]

The good news is that there are very few components in a fuzz face. Take a look at the circuit board. You're looking for anything that looks brown/dark (like it caught on fire). If this doesn't work, stick your nose right up against each component and sniff deeply. You can often identify the burned out component by smelling it. Then it's just a matter of finding a replacement from the electronics shop and soldering it back in.

 

[Mincer]

Can you try it with a fresh battery?

 

[jeremy]

i bet ya fried it but im sure it can be fixed

 

[superpete]

I think you meant milliamps there. And yes, voltage is the "pressure" applied. Current is "drawn out" based on that pressure.

me??? make a mistake??? no...never! that was a test, and you passed!!!

yeah you're right. i meant milliamps.

 

[Artie]

:beerchug:

 

[JOHN FUZZY]

Can you try it with a fresh battery?

I tried the same battery on other pedals and they work

 

[jeremy]

right. im guessing you fried it. open it up and take a look. there arent many components in a fuzzface so you may be able to see what fried

 

[devastone]

Like many have said, it is only rated for 9V and 12V probably fried something. My guess is there is a 9.1V zener diode from the adapter input to ground that blew from trying to dump too much voltage (the ~3 extra V) and is now a short to ground. Unfortunately, if that is the rectangular box fuzz, it may be all SMT components so you may need to find someone that can deal with those.

 

[GuitarStv]

Like many have said, it is only rated for 9V and 12V probably fried something. My guess is there is a 9.1V zener diode from the adapter input to ground that blew from trying to dump too much voltage (the ~3 extra V) and is now a short to ground. Unfortunately, if that is the rectangular box fuzz, it may be all SMT components so you may need to find someone that can deal with those.

Ah. Hopefully not. SMTs are a bitch to try to fix. If it's normal components you're only talking about 2 minutes of soldering.

 

[ErikH]

Like many have said, it is only rated for 9V and 12V probably fried something. My guess is there is a 9.1V zener diode from the adapter input to ground that blew from trying to dump too much voltage (the ~3 extra V) and is now a short to ground. Unfortunately, if that is the rectangular box fuzz, it may be all SMT components so you may need to find someone that can deal with those.

This. That diode goes and nothing will power it.