No bootable device means that your PC is not seeing your hard drive (HDD) to load Windows from. You could say that your HDD has failed BUT it is concerning that your keyboard barely functions and that there are no options from Boot Manager, which points to problems with your BIOS or motherboard.
At this stage it could be any of the following. Power problem. Keyboard problem. Motherboard problem. BIOS problem or a combination of them.
You have two options.
1. Contact a computer repair centre or person, explain the problem and ask for a quote.
2. Recover your data and try to troubleshoot the problem yourself.
There's a fair chance that your HDD is probably alright and that you can recover your data from it.
To do this just google "how to connect HDD from dead laptop to another PC" There will be numerous hits. Select the one you feel most comfortable with.
Remove the HDD from your laptop to recover your data, so that you can continue working on another PC (see above) and then try to troubleshoot what the problem is. Once you have recovered your data from your laptop HDD you can reinstall it so that you have a complete pc to work with.
Here is a link to the Acer E1-531 service manual http://www.manualslib.com/manual/440295/...