If the scaler chip was reballed (solder pads replaced) by a professional using softer solder than originally used then in theory it should not have to be baked again. Baking doesn't replace the solder, it simply melts it to get rid of the microfractures. If the scaler isn't cooled properly baking becomes an ongoing thing.
In practice nobody trusts the scaler chip to not overheat regardless of what solder is used, hence the heatsink/fan mods. If you keep the scaler cool enough (mine stays below body temperature) then it doesn't matter if you reballed it or just baked, it will work and keep working until something else breaks - in the 305T's case bad capacitors in the power supply/inverter board will eventually fail. Fortunately if you know your way around a soldering iron they are cheap and easy to replace.
I baked my XHD3000 scaler board over 2 years ago and it still works fine. Mind you, I went a bit extreme in my quest to keep it cool by keeping the back case off, mounting a heatsink directly to the scaler chip, and using a 60mm case fan (powered by the 5V line of a USB hub to keep it quiet) blowing sideways to keep it cool.
If the previous owner did the mod right, he cut the RF shield and mounted the heatsink directly onto the scaler chip. If he didn't then unless he went crazy like me on the other cooling factors it has a chance of overheating again if it is really pushed hard eg. spending a long time working continuously in non-native resolution.
Just for the record I have never had to bake any of my scaler boards more than once, but again I take major precautions against overheat.
In practice nobody trusts the scaler chip to not overheat regardless of what solder is used, hence the heatsink/fan mods. If you keep the scaler cool enough (mine stays below body temperature) then it doesn't matter if you reballed it or just baked, it will work and keep working until something else breaks - in the 305T's case bad capacitors in the power supply/inverter board will eventually fail. Fortunately if you know your way around a soldering iron they are cheap and easy to replace.
I baked my XHD3000 scaler board over 2 years ago and it still works fine. Mind you, I went a bit extreme in my quest to keep it cool by keeping the back case off, mounting a heatsink directly to the scaler chip, and using a 60mm case fan (powered by the 5V line of a USB hub to keep it quiet) blowing sideways to keep it cool.
If the previous owner did the mod right, he cut the RF shield and mounted the heatsink directly onto the scaler chip. If he didn't then unless he went crazy like me on the other cooling factors it has a chance of overheating again if it is really pushed hard eg. spending a long time working continuously in non-native resolution.
Just for the record I have never had to bake any of my scaler boards more than once, but again I take major precautions against overheat.