Is it over? 21NYC Sansamp Bass DI

[animal]

The bass player in my band fried his Sansamp pedal here. I have dis-assembled it to check it out and cleaned out the fried parts. I contacted Tech21 to get the replacment resistors and diodes, the engineer gave me a slightly cryptic response but I think I can sort it out.

After a little more work on cleaning up the board today I am thinking that it is too burned up to repair.

Opinions?

[ATTACH=CONFIG]46411[/ATTACH]

FIRST TO ALL I DON'T KNOW HOW PUT A SMALL PICTURES SORRI !

Man i have exactly the SAME problem !!!!
how you fixed??

I replaced all component, two diodes, one zener, and the resistor:
D1 and D12 = 4148
D15 = 10V Zener Diode
R109 and R54 = 68 Ohms

but when i plug de current, the resistor burns...again
The tracks was erase for cause the burned, but i try to figure out seem some pictures, included yours, so...maybe i made some mistake on the tracks, but i can't figure out because....is burned !!! ajjaja
here is some pictures:






would you help on this?

* Sorri for my english, am from Chile.

thanks for advance !!!

[J M Fahey]

Q´hiacéi güebón culiau!!!! ... ya tomaste once? .... je je je

I congratulate you on having traced the schematic and built it on a *separate* piece of board.

Los gringos compran otro y ya está, nosotros *tenemos* que arreglarlo

1) First you have to fully remove all traces of burnt PCB material, use a small Dremel drill head:



, I add a dental hook to scrape carbon away.

Otherwise conductive carbon is still shorting your supply.

2) put a limiting resistor in series with +9V supply, say 10 or 22 ohm, 1/4 W

Buy a dozen of them, you will use them as "fusistors", for the dual purpose of limiting current and burning themselves out in case of full short, the idea being that they will somewhat protect the damaged PCB and let you measure something.

PCB straight to supply will keep burning and a fuse will blow in 1/10th of a second before you can react.

Resistor will last a short time and let you measure something.

First measurement is how much voltage reaches the preamp board:
* zero V showing full short?
* a couple V meaning something is drawing too much current?
Not the same.

As a side note: search the Net, I am quite sure "somebody" , specially the "pedal guys", has traced and published a schematic.