I have a Pavilion 7966 (about 5 years old). Recently it refused to boot, with the message that no hard drive was found. After a lot of reading forum posts on the internet, I started with the most simple item first, I replaced the internal lithium battery. Lo and behold, life resumed - and the computer seems much more responsive, too.

However . . . I have been smelling an odd smell on and off for awhile now and recently realized it reminded me of a transformer going sour. The PSU is original and is a 200W ATX-1956D. I have two internal hard drives - a Maxtor (180Gb I think) and a West Dig 250gb. I also run two DVD drives, one a burner (Plextor) and the other a reader (not sure of the brand). Floppy died several years back and was not replaced. Video card was upgraded somewhat. The ethernet function embedded on the motherboard died about 2 years ago and was replaced with a PCI plugin.
The PSU has the 20 pin going to the motherboard, 4 cords powering the 4 drives (a fifth for the floppy which is not used - taped over), a four pin that connects to the motherboard and appears to supply power for the CPU fan, and finally a 3 wire connector which disappears back behind the drives and connects to the front of the motherboard.
It would seem wise to me to 1)replace the PSU and 2)upgrade to a more powerful unit.
I'd like to put in a 300W unit. From there I'm kind of at a loss. The replacement must physically fit where the old one goes and also supply the right number and type of connectors (not concerned about the floppy). Reading online, I'm not finding a clear choice. In fact, I'm not finding anything (upgrade or replacement) that fits, and has the right connectors. The complete phrase on the side of the PSU is BST ATX-1956D A1, if that makes a difference.
Perhaps this will require camping on the phone? Any comments/suggestions/direction is gratefully appreciated.

welcome to THF

before you try and find a PSU have a look at this site it'll give you some idea how much power you need

http://www.extreme.outervision.com/powercalc.jsp

the PSU is a micro ATX form factor

here's a site with some power supplies on

http://www.beachcomputers.com/atx-1956d.htm

Jeff - Thanks so much

The calculator was an eye opener! I was guess-timating and was low. Interesting to know that PSU's loose their oomph after only a year or so. I may have been living (computing) on borrowed time.

The Beach Computer site was the best match yet!