When someone asks advice about some fault in a particular model car, the first question will be what production year it is. The internal details change a lot from year to year.
This radio model isn't quite that bad as a year-to-year thing, but it has been sold long enough for the transmitter's power circuits to have changed in a big way, especially since 2006-2007. If it's older than that it used conventional bipolar transistors in the transmitter's RF power stages. If it's newer than that, the radio was built to be lead-free. This means both lead-free solder and lead-free parts. The original RF power transistors used in the transmitter's power stages were discontinued by 2007, and the factory adopted a substitute called a IFR520 MOSFET. It just does the job but tends to be kinda fragile against high SWR. Yes, the older type transistors can fail, but they tolerate higher levels of stress.
The calibrated eyeball is your best first tool to see what the problem may be. Along the aluminum plate heat sink at the rear of the main circuit board you'll see the RF driver transistor at the far left, and the two "final", or main power amp transistors side-by-side to its right. With any luck yours don't look quite this bad.
The "pop" you heard is no doubt connected to your "no transmit" problem. The noise suggests that one part or another will appear physically damaged.
If you do find this kind of failure, there will also be other faults that are not so readily visible. What tools do you have for finding "hidden" failures in parts that look as if they are okay? A multimeter, wattmeter, dummy load are a big help. An oscilloscope is an unfair advantage.
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