I picked up an HP s7220n dirt cheap, then I found out why. It powers on just fine, boots, runs for a few minutes, then powers itself off. At that point, the power supply is hot enough that you don’t want to touch it. Effectively, it’s a Useless Machine with an Intel CPU and Windows XP.
The s7220n and other HP Slimlines use a more or less standard micro-ITX motherboard, and the power supply’s form factor isn’t terribly rare, though people can’t seem to agree whether to call it a FlexATX, Mini ITX, or something else. But HP used a miniature 24-pin power connector on a lot of its early slimlines (the situation may be different today). I’ve seen it called a mini ATX or an ATX Small, and that is rather rare.
FSP makes a drop-in replacement. It bolts right in and has the right plug, but it’s a higher wattage, so it should be more trouble-free than the underpowered factory original. You can get one off Amazon for about $52, shipped. That’s a lot more than a 200W standard desktop power supply, but not outrageous.
Another option is to get an FSP270 and a mini ATX adapter. You end up paying a little more, but you get 70 more watts of headroom and better upgrade options in the future, since you’ll be able to remove the adapter and drop in any off-the-shelf mini ITX board. These parts aren’t guaranteed to be available forever, but I linked to them so you can at least see what they look like. Similar parts should remain available for some time to come.
I’ve also heard of people lopping off the connector on a standard power supply and splicing the HP connector on. I’d be more inclined to do that with a 24-pin extension cable instead, so it’s not permanent. Whether doing that is worth the $10 you save is up to you to decide. If you already have a supply of shrink tubing and a heat gun and a good set of wire strippers, and enjoy doing that kind of thing, it might be.
I want to fix the machine, because it really is tiny. I have books bigger than this computer. Or, for those who remember them, it’s not all that much bigger than an old Commodore floppy drive. And you can stand it up on its side or lay it flat, depending on how your desk is set up.
But, since it dates from 2005 and wasn’t a high-end system even then, it is showing its age. It’s new enough to have SATA, but it has a 1.5 GHz Celeron M CPU and the memory tops out at 2 GB. It appears that it can take any standard voltage Socket 479 Pentium M processor for an upgrade, which means it can go up to 2.27 GHz and still maintain a perfectly reasonable TDP of 27 watts. But high-end Pentium Ms aren’t easy to find, and when they do turn up, they’re an $80 part. They’re not like older Socket 775 CPUs that you can buy all day for 30-40 bucks.
Rather than replace the power supply and upgrade the CPU, I’ll be happier with a motherboard swap and a new power supply.
The difference in price between a CPU swap and an Atom D510 motherboard (or a D525 board, which bumps the speed to 1.8 GHz) is about a wash, and I’d end up with a more modern system–SATA 2, 4 GB RAM, two CPU cores, and the ability to run 64-bit operating systems on it. For web browsing and word processing, it would be fine, and it would run cool and quiet and not use much electricity.
If I wanted more punch, say, for video conversion work, I could spend more to get a board that can take a more mainstream desktop CPU and more memory, like an Intel G41.
If you’re looking to do a motherboard swap, you can either buy the 270W power supply listed above, or if your power supply still works, buy an adapter to convert the stock power supply to standard ATX.
From reading reviews of various motherboards on Amazon and Newegg, it seems a lot of HP Slimline owners are taking that approach. And I think these machines make sense to upgrade. There’s nothing wrong with how the machines look, and the small size isn’t the liability that it used to be. You can put a 2 TB drive in the single 3.5″ bay, and you can always add more storage via USB or eSATA if the motherboard you put in supports it. The small size means you can get by with a smaller desk, and you can move it around easily if you need to.
I think if you upgrade one of these with a dual-core Pentium or Athlon motherboard and CPU, you’ll have a useful machine for several years. And by the time that’s obsolete, you’ll have a lot more available choices. I think micro-ITX has a long future, even if it isn’t destined to ever be quite as common as micro-ATX.