Recently my HP 6510b laptop’s adapter died, actually the connector had some loose connections so it wasn’t charging properly. I tried many local repair shops to see if there was a replacement connector available, it uses a 7.4 mm x 5.0 mm connector with a central pin, but it wasn’t available anywhere.
A new HP Original Adapter costs 1.8k to 2.5k and I wasn’t willing to spend that much for a simple connector problem. So I was checking eBay and saw this replacement adapter for my laptop for about $10 only. Anyway ordered it and I got it really fast i.e. within 12 days Hong Kong to India by Normal Airmail.
The adapter looks just like the HP Original one and is working fine. So if your adapter is dead, check eBay for cheap replacement adapters.
I also found a seller who is selling the 7.4 mm x 5.5 mm connector and ordered two including the cable. The two cables alone came to $10 shipped. I received that too few days back, will be installing it shortly on the old adapter. :)