I'm not meddling with hardware! I'd brick the machine if I did. What I am doing is dumping my partitions regularly, so that if bigboy does finally breathe his last, I won't have lost anything vital.

I just googled to discover when this model came out (it's an HP Compaq dc5800 if anyone is interested); according to the user manual, it was 2008. Well, what can you expect of a nine-year-old computer? They do wear out sooner or later if heavily used.

If I do lose bigboy, I'll bite the bullet and buy a modern machine (a tower if I can find one).

It's just the power switch, it shouldn't brick the machine (it may cause it to burst into flames though - Ooh! nasty! worst case scenario )
Surely you know some techy person who could cast an eye over it and save you some money with a new switch?
Maybe you'd like to consider a second hand ex-corporate box from a broker like ijtdirect or Morgan computers. More bang for your bucks sort of thing. I'm running a "new" (to me) HP Z400 workstation with quad core Xeon processor, 16Gb of memory and a 2Tb disk, the whole box is circa 2009 from what I can find out. Just short of £400.00 Works fine, no uefi to worry about, I use it for CAD and to drive my 3D printer. My home brew box became too flakey and i couldn't be bothered building another.

Play Bonny!

It's not just the switch. The bios is playing up too (there's another thread on that). It's definitely old age. Like me!

I have a suggestion based on the fact that my reset switch was failing. It might seem strange but bear with me.

first your tower may allow your front panel to unclip, mine has plastic lugs that you start to pull from the bottom of the panel.
I have reversed my reset and power leads but leaving the wires to the panel alone....swapping at the motherboard.
I show the panel connectors even tho your colours may differ from mine.....red and white with white being the "common" for this mobo

To the left is the front usb connectors then the power switch (was the reset switch) then the led wires with white as "ground"
http://imgur.com/a/OIUo7

2) not much can be seen in photo of the new cable swap at the mobo but I show it in any case
You may be lucky and the connectors may be labelled
http://imgur.com/a/BA6Lt

3) and the most important bit is to download your mobo manual and look for the area for the power switch and reset,
then trace and match those connectors and swap both the ground to ground and power to reset
http://imgur.com/a/pPYzX

4) so it is not essential to look at the leads behind the front panel!

it just helps to clarify in your mind.

turn off PC at mains, leave off during swap.

no need to buy static wrist strap, don't move your feet, just touch back of hand to metal case and pull off connectors and swap them

let me know if you want a hand reading your manual by linking to it
and a photo of pins area in "as is" state can also help

good luck

Older desktop style machine? Sounds like issues I've had with PSU's going bad. Sometimes plugging them into a different circuit in the house improves things. Too many things on a plug or it draws more power with age, IDK. I tended to just replace the PSU every 3-ish years back in the day. Only $30-ish back when a cheap computer was $500+. One time I just opened the case and blew a $10 walmart fan on it cause I was too cheap to replace the PSU. Now you can get a pretty decent machine, laptop even, for about $300-ish. As long as 10yo specs are still good enough for you.

hazel,

First ask if the Harrow Computer Club can help. Some people change their computers on a regular basis.

You may find this of use.

Novatech Desktop PCs for Home:
https://www.novatech.co.uk/pc/home/

Example:
Novatech NT1267:
https://www.novatech.co.uk/pc/range/...ifenti267.html

The base model (£310 plus delivery) is probably okay with no OS installed, 4GB RAM, Intel Pentium Dual Core G4600 3.5GHz Socket LGA1151 (Kaby Lake) Processor (rated at 5448) but you can customise it to suit your requirements.

Also, CCL Computers:
http://www.ebay.co.uk/itm/Hyper-CCL-...Oo5iYa215swVwQ