Flickering power light Dimension 5150

[Benerang]

I restored a dimension a couple of years back. Suddenly I can't get it to boot up. All I get is a rapidly flashing red and green power light. Anyone know what the problem could be? Would really appreciate it as this dimension is my editing station currently.

 

[Deleted member 1898488]

http://downloads.dell.com/Manuals/all-products/esuprt_desktop/esuprt_dimension_desktops/dimension-5150x_service%20manual_en-us.pdf
take a look at page 62.
...not seeing that, but what are the diagnostic lights on the back like?
any beeping?