tablet wouldn't power on

@mdawes67 you are not giving us a lot to work with:-) It would be nice if you could let us know what you have tried etc. Anyhow, first thing you want to do is to check your charger. Make sure that it delivers the proper voltage. then check your cable make sure that it is working properly. Next check your mini-USB post to see if there is any lint, dirt corrosion etc. preventing it from taking a charge. After that you would have to disassemble your tablet and consider replacing the battery. While you are there check to ensure that the charging port is still fully connected etc. This video up to 3:24 will show you how to get to the battery.