blown up boss distortion

[DavenPaget]

wow, so i guess it's cooked alright!! wondering...could any of the transistors if blown have acted like a diode bridge? that could maybe explain the voltage doubling?

i saw the adapter he used...it was a 12 vdc...that should not have blown the damn thing! it's only gonna draw 9volts!!

the can from the cap was literally rolling loose below the circuit board, and i had to de-fluff the whole area from all the crap from the capacitor.

good call on all the electros and diodes...a bad diode can inject a dc hum like that too.

i have the pedal, when i get a chance, i'll post specific voltages and what i find.

really weird!!

Right . Most plugs not meant for guitar pedals are unpleasantly center positive .
Remember that blowing certain diodes and trannys can turn them into dual conduction bridges , therefore the 16V ( should have been 18V but diode's drop . )
Damn right , you have to look forward to do the classic silicon and aluminium can replacement .

[ashcat_lt]

i saw the adapter he used...it was a 12 vdc...that should not have blown the damn thing! it's only gonna draw 9volts!!

I think you've got your amps and volts mixed up there, dude.

Also, by definition pure DC doesn't make a sound.  The lack of filtering caps on the supply might cause a hum, though.

It was definitely a polarity problem.  Kind of frustrating when folks post that a PSU is xVDC without specifying polarity.  As you've seen, this makes a huge difference!  This particular pedal also illustrates the reason that this type of "polarity protection is completely wrong.  A diode in series with one of the power rails would simply have blocked the wrong polarity power and everything downstream would still be fine.  No fuse necessary.

[pinkjimiphoton]

yah, that's the chip in it..its an SIP..Single Inline Package..dip means dual yada yada.

thanks guys...imay look at it today if i get to it.

[MikeH]

i saw the adapter he used...it was a 12 vdc...that should not have blown the damn thing! it's only gonna draw 9volts!!

Any time that diode is fried, it generally means reverse voltage.  Exploded electrolytes is a dead giveaway too.

Was it a 1spot?  I have 2 1spot wall warts, 1 9v and 1 12v.  They are opposite polarity.  I am constantly afraid that I will mix them up. 

[DavenPaget]

i saw the adapter he used...it was a 12 vdc...that should not have blown the damn thing! it's only gonna draw 9volts!!

Any time that diode is fried, it generally means reverse voltage.  Exploded electrolytes is a dead giveaway too.

Was it a 1spot?  I have 2 1spot wall warts, 1 9v and 1 12v.  They are opposite polarity.  I am constantly afraid that I will mix them up. 

And have a pedal 'name' Cooked ready for breakfast !

[pinkjimiphoton]

it was one of them generic ass multi voltage wallwarts....the kind where you can change the plugs for size and polarity. i bet he had it set backwards. i've used 12 v warts before into a 9v pedal with no problem.

[DavenPaget]

it was one of them generic ass multi voltage wallwarts....the kind where you can change the plugs for size and polarity. i bet he had it set backwards. i've used 12 v warts before into a 9v pedal with no problem.

Yep . Most standard warts have opposite polarity to what we do .

[pinkjimiphoton]

but i mean...damn, i have never seen one smoked like this tho!!