Resistor values are coded by the colors of the bands on them, if those colors are burnt away you'll need to find a pic of the board to reference. If they are burnt it is likely that the traces they attach to are also damaged so you may need to wire around the damage. If you are a skilled elec tech you can do this but soldering very small components is not fun. In the old days we would replace them but I haven't done it in years.

Resistors do not control a function per say they are there for reasons of controlling and modifying the flow of electricity in a circuit. Actual control is handled by a logic chip or other cpu.

You may be able to find a used PCB on ******** or other source that saves you the work. Or maybe you like a challenge? Edit: forum won't let me mention e bay , although this site shows it unavailable

If you are set on trying to repair this here is a resistor color code chart to help ID them:
http://www.resistorguide.com/resistor-color-code/
Once you know what you need you can buy them easily through any number of sources.