I have seen this problem posted on this forum more times than I can count LOL.
Its mostly with laptops which are hard to diagnose internal problems.
I have tried to the best of my ability to pin-point the most likely cause and solution, the HP web site has pretty much one solution which you have already tried as you posted above.
Only thing I can suggest is taking the laptop apart and gaining access to the processor and see if something is blocking air-flow or if the heat sink is clogged with dust.
The laptop is fairly old and could be suffering from either corroded internal connections or a component is failing.
A laptop is put together with modular connections, which is ribbon wires with conductive copper ends wedged into compression sockets, they are not soldered like in the old days of solid state electronics. Everything seems to plug in rather than be soldered in. When two metals of different chemistry are mated together this way, they tend to react differently to air and humidity (water vapor) and the results are corrosion. Corrosion can create a barrier that eventually separates the two un-like metals and thus creates a dead or open circuit.
I gave you a brief piece of electronics theory here, so it might help you to realize that the solution may be taking the laptop apart and disconnecting all of the modular parts and re-connecting them.
This process disturbs the corrosion and makes the connection a closed circuit again.
Taking a laptop apart is not easy the first time around and I suggest if you attempt this, you keep track of how and where everything goes when re-assembling it again.
This web site below is for several Toshiba laptop disassemblies, but if you click the numerous links on this page it might give you an idea how to take your laptop apart.http://www.irisvista.com/tech/
By the way this site is free, each set of instructions has links near bottom of each page for the next page with continued instructions such as page 1 page 2 page 3 etc.
Hope this helps you, at the very least, you'll learn how to disassemble several Toshiba laptops
Edited by MrBruce1959, 29 May 2010 - 01:49 AM.