Can anyone advise on the following, have a damaged power supply for a laptop rated at 19.5v 4.7a and also have a good used power supply rated at 19.5v 6.15a

can I use the second one on the laptop will there be any damage potential to the laptop?

The ampage is the maximum potential supply the transformer can give..... so providing the voltages are the same.... it will work just fine! its not a toshiba power supply thats broken is it?..

Yes the higher current rated power supply will be fine.

Using a supply rated less would cause the ps to overheat, and fail.

nope a sony one where a rabbit has chewed the wires and its shorted out , I have a couple of spare toshiba satelite ones spare as well