My hp w1907 will not turn on at all. Cabling is good and supply lead is good. Please, what should I check for inside? (assuming I can open it up) Is there an internal fuse that may have blown?
If it's out of warranty but less than 5 years old I'd return it to the retailer -- it's his problem not yours.
However, if you want to DIY, there have been a lot of failures in flatscreens due to defective capacitors in the PSU. These can sometimes be identified by bulging or leakage -- but even if there's nothing visibleand your soldering skills are up to it, replacement is cheap and easy. A de-solder pump is useful.
Just ensure that you observe the correct polarity when reinserting and select components of the correct value-- and the same or better voltage/temperature rating.