The transmit meter light on the SR-447HPC & SR-497HPC can be changed to different colors, which is the reason your radio is set of yellow. The fact that it's flashing rather than solid is what indicates you have a problem. I would recommend using an external SWR meter to check your antenna system. If you determine your SWR is low (less than 2), then it's likely the radio needs to be repaired.
For out of warranty repairs, you can contact Greg @ Wakulla Electronics. He is familiar with the radios and very knowledgeable. Below is his contact information.
2219 Crawfordville Hwy