The way to determine what value resistors you should use in doing replacements requires that you very carefully measure the DC voltage at each end of the resistor in question in the working circuit. Determine the difference in voltage between each end, multiple that number by itself, and then divide by the value of the resistor in ohms. That will tell you the power being dissipated by that resistor in watts. (V squared divided by R).
Then select a resistor with at least three times the power rating you came up with and if the part is going to put out 1 watt or more, mount it clear of the PC card to provide additional cooling space.
Note that at turn on, some resistors may see substantially higher surge voltage then in steady state operation. Make sure your choice of power ratings takes this into consideration. The reason resistors fail in a circuit is almost always that some active device (transistor, tube or IC) failed and this caused the voltage across some resistors to be MUCH higher than their design ratings and thus overheat and fail too. The circuit damage hardly ever is caused by a failed resistor (if it was properly specified in the original design) but is collateral damage.
Example: a 5000 ohm resistor with 50V at one end, 10V at the other end. Voltage drop is 40V. 40 x 40 = 1600. 1600 divided by 5000 = 0.32 watts. You would need a 1W rated resistor in this case (2W would even be a better long term choice)
Frank Van Alstine