Shadetree, typically when that combiner resistor fails its due to output issue or SWR. Considering that you antenna SWR is likely fine, I would look into not replacing the 2w with a 5w resistor , but more likely your issue is that ceramic disc capacitor failed creating a matching issue on output. You will likely have to replace that and preferably tune the output with a capacitance tube that offers variable Capacitance. Not sure what Voltage rating is on that cap but, my guess that's the culprit . I wouldn't cover underlying issue with bigger resistor . GL