replacing resistors

[iwantomakenoise]

hi

im new to the circuit bending scene but i have great ideas. So far i have circuit bent a walkie talkie and it sounds good but I want some help with replacing resistors with pots? how do you know if its possible and how do you find the best place?

cheers

D

[Circuitbenders]

A lot of replaceable resistors can be found with the lick your finger and poke the circuitboard technique. If something happens narrow it down to which solder point is creating the effect and replace that resistor, if it is a resistor.

Otherwise , find a likely looking resistor and temporarily bridge it using a pot of equivalent or higher value. When you turn the pot and the resistance goes lower than the bridged resistors value, the current will take the path of least resistance and you'll get a rough idea of what would happen if you replaced that resistor. Remember that you'll only get the effect of what would happen with a LOWER resistance. To find out what will happen with a higher resistance you'll have to actually remove the resistor from the board.

It really helps if you have some kind of electronics knowledge in order to select which resistors to try but as with most things in circuitbending, stay away from where the power comes into the machine. Bear in mind that most circuits probably won't have any resistors that you can just replace at random and create good effects. Unless its an analogue machine i'd be surprised if anything has more than one or two, if that.

[squid_ink]

I sincerely apologize for the extremely noobish question, but how exactly does one go about actually removing/replacing the resistor?

I know which resistor I want to replace with a pot, but honestly, I have no idea how to remove the tiny thing short of trying to cut it in half and soldering wires to the ends. It's one of those itsy-bitsy resistors that hug the board, not a multicolored, cylindrical type.

If anyone could explain the process or point me in the direction of a guide, Id appreciate very much.

[catweazle]

I think you mean SMD (surface mount devices)



SMD resistors and capacitors (resistors have numbers on them , capacitors not) can easyly desoldered by alternately heating each side for a short time (about 1second each side) with your soldering iron. After a few cycles (heating left, heating right) the part will left the circuitboard (PCB).

[squid_ink]

That answers my question exactly! Thanks for the info and I look forward to trying that tonight!