The Case of the Dead Mini5SX (leadedsolder.com)

Thanks OP! That was a lovely writeup.

I hope that you got to see many more Carp games, Yoshikatsu-san.

Fascinating restoration. You should post this on Hackaday.

2 glued transistors + thermistor in the middle = "tempco" (temperature compensator). Used in VCOs to compensate for frequency changes brought by ambient temperature changes. Maybe the backlight is PWM-based?