Burned resistor in my RAT! dangerous?

[add4]

Hello everyone,
I opened my RAT right now to plan the modifications to the Fat Rat, and add some other mods, and I noticed that one of the resistors is burned, it's all black i can't read the colors anymore.
Pictures of the barbecue are here :https://picasaweb.google.com/117920779036489015072/ProcoRat#
I have several questions about this :
- How can this happen? I only made the ruetz mod on a switch, and added another switch for asymmetrical clipping.
- Can this be dangerous for the pedal? for me? i know these are not high voltages, but won't it heat something else that shouldn't be heated as much?

I think this is the 47r resistor between the V+ and the capacitors/diode part that i see in lots of schematics but don't understand what they're here for
Any idea?
Thanks in advance.

p.s. Should i be careful in changing components values then? or could it be caused by bad alimentation, or just a bad component?

[Fender3D]

You burned that by bad power supply, maybe you reversed polarity for a short time and D1 got is revenge (check it too)...

About mods,
check always with a schematic what you're doing, not just pictures. 

[add4]

You burned that by bad power supply, maybe you reversed polarity for a short time and D1 got is revenge (check it too)...

About mods,
check always with a schematic what you're doing, not just pictures. 

Reverse polarity is possible!
i have several mini jacks power supplies and i think one is reversed yet i used it when i couldn't find the other ... ^^.
I usually know what i'm doing, well starting to... :p
Thanks for your advice i was really curious on how it could have happened.
I'll check D1 too.
Could it explain why it sounded so bad? or is it only because it's a stock newer RAT? :p
Thanks for the input

[Fender3D]

...
Could it explain why it sounded so bad? or is it only because it's a stock newer RAT? :p
Thanks for the input

It depends on what value has got the resistor...
It may vary under load also.
Surely a new part will do whatever it should... 

[cpm]

i burned mine with reversed 24v !!
by the way, replacing that is what got me started in stompboxes...

[petemoore]

I have several questions about this :
- How can this happen?
  Current through a resistor = heat, so..enough current to fry it occured.
  I only made the ruetz mod on a switch, and added another switch for asymmetrical clipping.
  It's pretty easy to 'inadvertantly modify' when modifying, suspicion that a trace was created enough 47R-heat to get an RBQ going.
  Can this be dangerous for the pedal?
  Yes, heat can damage everything, as can overvoltage or reverse voltage and AC voltage [applied to a DC circuit.
  for me? i know these are not high voltages, but won't it heat something else that shouldn't be heated as much?
  Solder joints can fail, traces can be BBQ'd and scorched by heat, fixed resistors are heat resistant components when compared to say an active, diode or capacitor.