Hi,
If the HDD or SSD is malfunctioning it can confuse the Bios to the point it freezes..
Since you have already removed the battery and SSD with no change there is obviously a hardware problem somewhere..
The only thing else I can suggest at this point would be to remove everything removable and maybe try a different try a different keyboard and\or mouse..
Another thing to try would be to reseat the memory.. Taking it out, cleaning the contacts, and putting it back in might be the best step, but simply wiggling it around in it's slot could help as well.. If you have more than one memory module, you could try removing one and see what happens..
A very unlikely issue is that maybe the CPU and\or System fans have a problem and the machine refuses to do anything to protect itself.. If this were the case, I would think you would at least get a message of some kind indicating this..