So I got out my really old PSP1000 from many years ago and after using it for about 1 month, the problems with the right button on the dpad started about a week and a half ago. It started with the right button clicking by itself and I noticed that this happened whenever I plugged in the PSP to charge it, because as soon as I disconnected the charger the right button would function normally. Then nearly a week ago it started to pop-up a while after playing the PSP, whilst it wasn't even on charge and just yesterday the button would have problems after only 1-2 minutes. So I decided to open up the PSP, remove the LCD, replace the rubbery part and try and wipe the contact surfaces a bit, however in the process I broke one of the small 'lockers' for the smaller ribbon cable for the LCD. And now the right button won't even work, so it seems I have managed to break it somehow.
If anyone has any advice, it would be kindly appreciated! :D