HP Laptop won't start - HELP!

Hi Guys and Gals,
Sorry to trouble you.....but.....
I have a HP Pavillion DV5 1112ea.
Still visually in pristine condition having never left my bedroom but it has developed a problem which, of course, is the reason I am here - lol.
When I press the start button (top left), all the lights across the top flash momentarily (as normal) and then there is a barely audible click from the top right (where the power cord thingy goes in); and I mean barely audible. There is no fan sound and it just sort of lies there like a table mat, dead, bereft of life, a computer no more. There is a little light where the power cord goes in and the charging light is nice, bright and pretty at the bottom left front.
I have done that 'remove the battery and all peripherals and press the start button for 20 seconds' trick so many times I've broken a nail.
I'm assuming the power bit is ok because of the two aforementioned lights being on and bright.
Any advice and help would be gratefully accepted.
Love and hugs to all who read this.
x