Hey, so I am still working on getting my Dell Dimension E520 (a kerb side find) setup as an XP gaming machine.

It was working until a few days ago, when it started an odd behavior. With the graphics card plugged in, I would flip the power switch and nothing
Well, sort of nothing, power WAS supplied, a CPU fan spun up, the hard disk spun up and I could hear from clicking from it, but NO video
I thought the video circuit was damaged in some way, OR the GPU had suddenly died.

Today I received another GPU, as I cannot use the original one (too large) and I plugged it in and same issue no video.
So, I removed the CPU, cleaned it a little and popped it back in in case there was a poor connection.
Now when switched on, it would power up for a second or so, and then it would appear to power down.
Then I removed both sticks of RAM and this time the board made POST error noises, Im assuming NO RAM was the complaint
I put the RAM back in
Turned it on, it came on, then switched off (as before) and then after another 2 seconds or so, it turned on again, and the video card worked 😀

So, this is the current state of play. It usually turns on after a small apparent shutdown, post PSU switch flip. And then it boots to XP.
In XP there is apparently no keyboard, which is also odd, as it works just fine in the BIOS.

Now, its been 20 years since I used a machine of this exact tech. Is this normal behaviour?
I'm wondering if there are some jumpers on the board I can use to turn on the machine,
more modern motherboards these days have a power switch on the board. But this chap is from 2006 so...