I purchased a Dell 15r laptop. The model # is 5520. The power plug is identical to the Dell 1501 that I have purchased many years ago. Therefore, I decided to test the new adapter from the 15r on the 1501 laptop.
My old adapter will not charge the battery. The error message is “The AC power adapter type cannot be determined. Your system will operate slower and the battery will not charge …” Therefore, the 1501 became a desktop.
With the new power adapter that came with the 15r model #5520, the battery charges. Therefore, it is apparent that the old power adapter is the problem.
http://www.acedepot.ca/ or http://www.mxmart.com/ca/ is the store that I decided to buy the power adapter from for 28 dollars. They are both apparently the same store that sells on Ebay and most likely other sites.
I am happy to say that the adapter works. The battery charges, but the adapter makes a humming sound while connected to the laptop. Therefore, there is most likely a chip inside that detects if a battery is installed. Although, I pray that the humming sound is not radiation emitting from the power adapter.
In any case, they sell various laptop batteries and adapters in Canada. Furthermore, I have an adapter that works on my Dell 1501 and possibly my Dell 15r model #5520.
If they are still open when I need a new adapter and/or battery, I will go there again.