Crud....I believe I fried my Marshall Bluesbreaker II stomp last night.  The battery burned out. I reached for a power supply...next thing I know....I smelled burning plastic.  It was appearently, not the right power supply for the unit. 
 
I quicly opened up the back side of the box and did a quick scan of the circut board.  I believe the black diode next to the power insert appears to be the culprit.  I have never done Stomp Box surgury before, but it looks like if I can find that diode, I could attempt to unsolder and solder a new one in place. 
 
I kind of liked this little silver Bluesbreaker II. 

I opened mine up and could make out '004' on D1 ... this agrees with the last entry here:
 
http://www.diystompboxes....php?topic=74245.0;wap2

Very cool, Bob. Exactly the info I was looking for. I have never soldered a printed circuit board, is there anything I need to be wary of during this surgery. I've changed out many a pick up, pots and guitar electronics....just no circuit boards.

My best suggestions are:
 
- take your time
- use as little heat as possible
- heat sink as best you can
- solder wick is your friend :)
 
The BBII pedal is one of my faves, although I don't use pedals much since getting a Laney IRT Studio  :)
 
 Good luck!
 

I've got a Hughes and Kettner Tubemeister 18w that has a really nice Marshall like crunch. I still really like the BBII as well.

With 004 marking could the diode be a 1N4004?  Also observe the polarity when installing a new diode.  One end will have a band on it.  Install the replacement with the band on the same end as the original.

and be careful not to lift the pads when removing the old diode.  as Bob said, use the least amount of heat possible to get the job done.

Also, along the lines of using as little heat as possible - use a soldering iron not a gun.  25W with a fine point for a tip.  Also agree on the solder wick to help remove the solder from the old component.

I'm hoping to swing by Fry's Electronics today, if I have time at lunch.....pick up the diode you all have suggested.  It appears that all of the local Radio Shacks have closed in these parts.  
 
Thanks for the advice Dave.  I have a small tipped iron that I can use, I believe that the heat wattage is adjustable on it.  

The interesting thing is that diode was there to protect the rest of the circuit board from certain death.
Make darn sure you put it back with the correct polarity.
 
I fried a Korg Poly 800 because of using the wrong power supply and was not impressed that it did not have that 2 cent part there to protect a then $1,200 synth. Was a hard lesson to learn back then when I was also very broke.  Hmm, actually I'm still broke! 
Ever since that day I am in the habit of clearly tagging all the ends of my power supplies. 
Right now I have my Scarlett 6i6, A Joe Meek Pre amp and a small Mackie mixer that are all totally different power requirements but use the exact same size connection for the wall wart. I do not desire to find out the hard way if they have that diode at the power supply input. 
I use little labels AND color coded stickies.