I am posting here as being forum closest to my issue. 

The cheap Veon TV I use as HDMI monitor suddenly started growing thin vertical coloured lines yesterday. It started with two but they have been steadily increasing. Yes, it is a cheap TV and can easily be replaced but I would like to get some diagnostic advice first. I know a little (not much) about this and am wondering what might be involved in fixing it. As it happens I have a second 'identical' model with failed backlighting on one side that otherwise still works fine. I put 'identical' in quotes because while the models are the same, the stands they require are not, making me wonder if the internals might also not match up. Advice and suggestions welcome. I am viewing this initially as an interesting DIY project. I have hobby electronics experience and am aware of the dangers of mains voltage and charged electrolytic capacitors.