Robbothecaveman

Previously working fully, now radio overnight stopped working. CD and tape fully functional. Having read so many posts about this, I bought a new radio on ebay for £25 tried that, used a separate chassi mounting antenna laying on dashboard, tried disconnecting CD player temporarily, still nothing. No sound whatsoever although the original radio did hiss a bit. What else can go wrong with the car to exhibit this? Getting very frustrated!!!!! If there is an antenna amplifier somewhere in the roof, it should at least have helped to try a separate antenna, surely.