Laptop not turning on.

without turning on the NB it will not be the Fan that is the problem as it isn't running at that stage. Try looking at the NB Battery as the possible culprit.

For spare parts it would help no end to know the brand name of the NB in question here and the same applies for a service Manual without a Brand & Model Number no one can even begin to suggest where to try for the Service Manual and other than suggesting places like E Bay for spare parts you will not get much joy there either.

As for replacing the Fans I would recommend that they all get replaced at the same time because NB's are very critical on these components & I would also suggest the use of a Cool Pad like the one shown here

http://www.antec.com/us/productDetails.php?ProdID=75004

These prevent anything blocking the Air Intakes from the bottom of the NB and also help to prevent the ingress of dust and other small items which can cause damage latter.

Col

Since any fan turns in its specified direction when current is applied to it (thereby it effectively turns to get rid of the current), if you ever turn a fan in WRONG direction, which you can tell from checking the orientation of the blades, the fan will actually begin to [u]generate current[/u]!

This current will then be fed backwards onto whichever component on the motherboard would have normally fed it to the fan. This is not good. ;)

"When I then connect the power supply to the laptop the power supply LED begins to blink".
Since this is happening when you connect the external power supply then you need to get another external power supply and test that out. Make sure the power supply jack is fully inserted into the A/C inlet.

Please post back if you have any more problems or questions.
If this information is useful, please mark as helpful. Thanks.

Here is a link to what is available on the site

http://h10025.www1.hp.com/ewfrf/wc/manualCategory?lc=en&dlc=en&cc=us&docname=c00375295&product=91451&rule=15119&

Testing an AC Power Adapter and Purchasing a Replacement AC Adapter

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00363266&lc=en&dlc=en&cc=us&product=91451&rule=12227

Keep us informed as to your progress if you require further assistance.

If you think that any of the posts that have been made by all TR Members, have solved or contributed to solving the problem, please Mark them as Helpful so that others may benefit from the outcome. ;) :D