[buggies]

I would not start replacing components without further evidence - especially on a pcb. If the unit is making a lamp dim I am surprised the fuse has not blown. You obviously have some sort of meter so a couple of voltage checks on the transformer output and across the 2200uF would be a good start and diode checks on the bridge.
Of course someone who knows something about the particular Sharp would have experience of their faults. I notice mention of the amplifier chip has been made and I know nothing about that side of it.
Maybe wait for a few more opinions.