Ross Distortion (Black) problem

[nordine]

hi all,

i have a ross disto (black version) and its giving me some troubles

i don't have with me a multimeter, so i can't measure anything, i'll only describe the sympthoms, for discard:

- when i plug the power in, there's this loud hum, as when you put incorrectly the polarity.

when i reverse the polarity, the hum is still there

also, in both occations there's sparks at the contact points, and the led of the transformer dies, like i'm shorting both poles directly ( for that reason, i've only connected the power supply for one or two seconds)

the thing was working just yesterday...

for now, i don't want to know where's exactly the problem, but i do want to know one thing:

could it be that the IC(4558) is burnt or damaged?

thanks

[petemoore]

when i reverse the polarity, the hum is still there
 does the circuit board have reverse polarity protection diode?

[nordine]

http://www.home-wrecker.com/ross_distortion_black.png

i think not (it's unmodded)

what gets me it's that this circuit is so simple, that i can't comprehend why it's shorting. i've taken off all jacks and stuff, and connected all directly. direct inputs/outputs, and power, but still maked that hum and sparks

[petemoore]

and sparks
 IIWM i'd insure no shorts between V- and V+ ]prior to further testing[ are occuring and find it if there is one.
 'did the battery start warming up?

[nordine]

mmm i've checked there are no shorts at least 15+ times

as for the battery, there's no battery, only a 9V transformer

and then again, returning to the original question: could this "sympthom" be associated to a burnt IC?

[nordine]

after seeing a friend set up his pedal, now i think...

he plugged the power supply (inactive) to the effect BEFORE turning on the 9V transformer

i recall FIRST turning on the 9V transformer, and THEN plugging it into the effect

(note that the power supply has an audio plug)


could it be that the very first short when plugging the audio plug was the one that fired instantly (maybe) the IC?

are they that sensitive?

please

thanks

[Mark Hammer]

The pedal requires nne volts DC.  What you are describing sounds like you have attempted to use a 9vac wall wart.  Is this true?  If the transformer does not say AC or DC using letters, but shows a wiggly line then it is an AC output.  That would explain both the sparks and constant hum.

[nordine]

:oops:

didn't know that

i'll check, then

thanks