Doddy,
That's a brilliant job, thank you!

I know most people want to just plug-and-play with modules but when you see how simple it is to fix some of the faults for yourself and realise how cheap some of the components are it saddens me to see people just give up and trash expensive modules that can be repaired for very little. Most faults with this kind of device will be in the power supply or output devices, all of which tend to be the large components that cost very little and are easy to replace as you've demonstrated. RS components will send you a bag of 5 new transistors for less than the cost of a pint, including postage!