Everything is getting more and more complex with electronics so much more to go wrong, as technology advances it can be difficult to maintain outdated electronics. The main issue with computers is the amount of wiring involved. I am an enthusiast but dont have much to do with trains, however I have plenty of experience working on buses and the older buses are much more reliable than the newer purely due to simplicity.
A number of the newer buses we have at our depot are suffering from lots of electrical faults. One of the main causes of problems is broken wires - one broken wire can leave the bus completely dead and can often take days or even weeks to find. Another problem which has cropped up recently on buses only a couple of years old is corrosion in the mass of wiring looms which are very complex, can take weeks again to work out exactly whats causing the faults, and usually the entire loom has to be replaced which is extremely complex. Another regular problem is sensor faults. Everything relying on data being fed into computers from various sensors, one dodgy sensor feeding false information causes a huge mass of problems. Its never ending! I am aware trains are built to a higher standard than a bus (in theory) but the same applies. The issue also applies to some cars from the last 15 or so years.
Just a thought, but the first point raised by a friend of mine who is a fitter at another TOC, and to be fair something that had crossed my mind also - in years to come the sliding step feature could become a problem when wear and tear sets in, the components get covered in muck, start to corrode etc, He said he can see them failing. If one jams in the 'out' position he would imagine it would trigger an interlock fault and render the train unable to move - possibly able to manually put it back in place and lock it(?), but presumably the train would then have to be taken out of service. Nice feature to have and definitely needed, but another complexity. I am aware that the class 390s have folding steps although a completely different design, I'm not sure if they have caused any issues over the years but somebody might know.
I hope the 777 proves to be the big success it has been promised to be, and as much as I love the old stock, it is overdue.
