signal cutting in and out

[Allan Lee]

A few days ago I noticed that the signal was cutting in and out on a TL-MR3040 that I had modified with an external antenna jack, on which I usually use a 5 dBi antenna salvaged from a non-functional TL-WR842ND. I think I may have overheated it during a trip recently by having it on for hours inside my backpack. See the attached image of the signal strength over time. Do you think it is toast?