Being that it's a microcontroller, it's not surprising to me that it might get rather warm. If you dig all the way to the bottom of the [link|https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/39755c.pdf|data sheet|new_window=true] to the product identification system for that chip, it does list some temp ranges. It looks like there is some variability since the data sheet is for a few different variants of this microcontroller, but it lists temp ranges potentially as high as 125 ℃ (~255℉). And even the variant which has lower expected operating temperatures, tops out at 80 ℃ (~175 ℉), which is within the range you gave, even if only just. That doesn't mean it's okay, but it's not running hotter than it's rated anyways.
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Being that it's a microcontroller, it's not surprising to me that it might get rather warm. If you dig all the way to the bottom of the [link|https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/39755c.pdf|data sheet] to the product identification system for that chip, it does list some temp ranges. It looks like there is some variability since the data sheet is for a few different variants of this microcontroller, but it lists temp ranges potentially as high as 125 ℃ (~255℉). And even the variant which has lower expected operating temperatures, tops out at 80 ℃ (~175 ℉), which is within the range you gave, even if only just. That doesn't mean it's okay, but it's not running hotter than it's rated anyways.
If you're going based on the theory that it could have been damaged by improper voltage, I would think your best bet is to see where that incoming voltage goes. What might it have gone to/through. It's hard to tell from the pictures,especially with the large display readouts. But these green PCBs usually have traces that are pretty easy to follow (unless they go to other layers of the board). Check with continuity mode on your multimeter if need be. But there's a chances that that main line goes to the DC to DC converter. In which case, it being damaged is definitely possible.
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I would concur with @oldturkey03 though, that having a short in the circuitry seems like a strong possibility, especially if it is getting toasty.
Being that it's a microcontroller, it's not surprising to me that it might get rather warm. If you dig all the way to the bottom of the [link|https://ww1.microchip.com/downloads/aemDocuments/documents/OTH/ProductDocuments/DataSheets/39755c.pdf|data sheet|new_window=true] to the product identification system for that chip, it does list some temp ranges. It looks like there is some variability since the data sheet is for a few different variants of this microcontroller, but it lists temp ranges potentially as high as 125 ℃ (~255℉). And even the variant which has lower expected operating temperatures, tops out at 80 ℃ (~175 ℉), which is within the range you gave, even if only just. That doesn't mean it's okay, but it's not running hotter than it's rated anyways.
If you're going based on the theory that it could have been damaged by improper voltage, I would think your best bet is to see where that incoming voltage goes. What might it have gone to/through. It's hard to tell from the pictures,especially with the large display readouts. But these green PCBs usually have traces that are pretty easy to follow (unless they go to other layers of the board). Check with continuity mode on your multimeter if need be. But there's a chances that that main line goes to the DC to DC converter. In which case, it being damaged is definitely possible.