Spent the evening inside my dead mini treadmill and the glowing bit was a red herring

Had almost the same moment of false hope with my walking pad last spring. Mine kept beeping twice and shutting down after a minute or two, and when I pulled the cover I saw a steady blue light near the front of the board and figured that was the fault indicator. Spent two evenings chasing that thing before I realized it was just the Bluetooth module doing its thing. The real issue was a little glass fuse tucked behind the power inlet that had gone dark inside. Took me forever to spot becuase it looked fine from above and I only noticed the discoloration when I tilted the board under a desk lamp. One thing I'd add to what worked for me: snap a photo of everything before you pull a single wire off. There were three connectors that all looked identical on mine and I mixed two of them up on the first reassembly, which gave me a whole second problem to solve. Also check the belt deck while you're in there. Mine had worn a dry patch underneath and the extra drag was probably what stressed the board in the first place. A few drops of the silicone oil the manual called for and it runs quieter now than it did new. Mine's been solid for about eight months since the fuse swap, so hopefully your part shows up quick and gets you back on it.

Mine never made it to the board inspection stage, and honestly I'm glad it didn't. When my compact treadmill quit mid-run last winter I was ready to grab a screwdriver, but I called the manufacturer first since it was barely eight months old. The tech walked me through a couple of checks over the phone and it turned out the walking belt had stretched and was dragging hard enough that the motor kept overheating and cutting out. No burnt smell, no scorch marks, just a belt that needed re-tensioning and a little silicone lubricant under the deck. Ten minutes with an Allen key and it's been running fine since. The overheating shutdown threw me off at first. It acts exactly like a dead unit until it cools down, then it runs again for a short spell, which makes you think something electronic gave up. Mine would go for five or six minutes, quit, then come back the next morning like nothing happened. If anyone's machine does that stop-and-recover pattern, it's worth checking belt tension and deck lubrication before ordering parts.

A scorched component under the board is a much clearer story than mine was though. Those little marked parts usually announce themselves when they fail. Hope the replacement shows up quickly and sorts it out.

Not sure I buy the bit about the dry deck being what cooked the board. My treadmill ran for years on a belt that squeaked like a dying cat and the electronics never flinched. Those little resistors ussually let go from a power surge or just age, not because the belt got stiff. I'd also be careful slapping oil under there based on a guess. Too much of it and the belt slips on the rollers, which causes its own headaches. If the deck really is bone dry the manual will say how much to use, and that amount is usually less than people think.

Agree with the person who called the manufacturer before grabbing a screwdriver. I did the same when mine quit one morning and the tech had me check a small reset button on the bottom near the power switch. The motor had overheated during a long session and tripped it, so I waited an hour, pressed it in, and it's been running fine since. Saved me from ordering parts I didn't need. One other thing, that dark mark under a component isn't always damage. Mine turned out to be leftover factory flux and rubbed right off with a fingernail, so check that before you pay for a replacement.

That R030 marking takes me back. We used to work these things out with a magnifying glass and a paper parts catalog, no internet to save us. Those low-value parts are usually in the current sensing path for the motor, wich means when one cooks there is often a semiconductor upstream that took the hit too.

I'd eyeball the big flat component sitting right next to it for any bulge or discoloration before you power up with the new one. In my TV repair days we called it the two-funeral rule, because replacing one and finding the second dead a week later got old fast. If the replacement lets go again right away, stop ordering parts and look at what's driving it instead.