SOLVED MBP Collosalus Smoking

[DeadAirMD]

Just built the Collosalus and was stoked to fire it up since I've always loved the MXR 117.......and it literally "fired" on up.

As soon as I engaged the pedal, I was only getting clean signal. Started to mess with the trim pots and smoke started coming up from the 22R resistor. Thought it was a bad component, so replaced it and the exact same thing happened again. The only component substitution I did was two 22uf 35v caps for the 15uf 25v caps. Pedal is running on 18v 100ma. What the hell did I do wrong!?!?

 

[Cybercow]

In the BOM for the MadBean "Colossus", the BBD should be an MN3007 - NOT an MN3207. R22 is the safety valve for the VD supply lines and with the MN3207 (which has reverse polarity of the MN3007) it likely is the cause of the over-current draw on R22. The MN3207 might be fried.

 

[DeadAirMD]

And now we're flanging!!!!

Man, great eye and thank you so much for taking a look. Getting old and worsening eyesight sucks. Glad I didn't fry the whole board.