The laptop in question is an old ASUS ROG model, which has some odd things going on. The HD may be gone or going...I'm not enough of a gearhead to make the call. In any case, since it's not booting up properly in W10, will I need to go into BIOS and change boot order to recognize the flash drive I'll be using to store the the software Bizman mentioned?
Acronis, the people that offer "True Image," also have a free program called Drive Monitor which will report the health of the drive to some degree. Unfortunately, you have to run the drive long enough for it to be analyzed. Since you are obviously concerned already, then I would plan to make the move and get it done before checking the health of the drive. It could be a simple problem with the OS, or it could be worse. There is no way of knowing with the information at hand.
I would change the boot order, image the drive to your SSD (Macrium Reflect), reset the OS, and then install the Drive Monitor program if you want to know the health of the HDD. No reason to bin the thing until you know the facts.
If you begin to experience audio anomalies and lost data then you want to think about replacing the PSU if possible (perhaps the brick power supply?), or prepare for the worst with a complete replacement.