JoolsP

Chris - where can you see Scan's delivery schedules? Can't find it on their website

Unfortunately, it's made no difference. The system still boots occasionally for 20 seconds or so before powering down and going back to the power cycling mentioned above - which by the way looking at it again is more like on for 1 second then off for a couple of seconds before repeating. When this happens, the H100 radiator fans spin up, but the case fans don't. Only when the system periodically gets past this loop to get further do the case fans get a chance to spin up. Not sure if this helps to point to a different cause? Looks like new hardware is in order.

Thanks for the input - I should definitely look at selling the CPU and RAM if I don't get another Z97 board. My son currently plays mainly Fortnite and Minecraft, and I'm thinking these games have relatively lower requirements in the thread-count and GPU departments. It was also partly about making as much use out of these older parts as possible, as they're perfectly good for what he currently needs. But as you say, more modern games are going to require a more modern level of hardware.

I've never looked at AMD processors before - thanks for the above recommendations - I will check them out if I go down the "replacement kit' route. Would this CPU potentially become a bottleneck if I one-day upgraded the GPU, or could it still compliment something like a mid-range RTX? I have an RTX-2060 Super in my current build, and the most likely route would be me passing this down to the above build if I upgraded my own GPU again in the future.

Can that cause the issue I'm seeing then? Can a thermal trip occur in such a short time, especially as I assume booting doesn't stress the CPU? It's definitely the cheapest option initially, and I'll give it a go. Cheers.

I didn't even think of the DDR3 not fitting modern mobos too - good shout.

Back in January 2015, I built a PC based on an Asus Maximus VII Hero, a Core i7 4790K, a GTX970 Gfx card and 16GB of DDR3 2133 memory. This worked great, up until late last year, when it suddenly wouldn't POST. It would power up, then about 3 seconds later, it would power off, and this cycle would continue until I switched the power off. Tested the PSU and even tried a new one, to no avail. I decided to buy a new motherboard, CPU, memory, PSU, cooler and Gfx Card However my son asked me to build him a gaming PC, so I thought I'd take a further look at the older bundle, and powered it up outside of the case. It still followed the above cycle, but I unplugged/replugged everything, cleared the CMOS, re-flashed the BIOS etc. and suddenly, at some point it randomly kicked into life. Happy days I thought, I'll build another PC from it. Got to the point of building a PC and installed Windows 10 on it. Windows 10 was doing it's initial set-up thing, and I had to go out, so I left it. When I came back, it was powered off. Then, when hitting the power button, it had gone back to the above power-cycling state. I have found that I can get the system to stop power-cycling if I unplug the CPU power connector from the Motherboard. Obvs it can't work like this, but it seems to stop the issue from occurring I'm thinking that it's almost certainly an issue with the motherboard, or the CPU. The issue I have is that this hardware is based on the S1150 socket, and motherboards with this socket aren't available anymore (other than the Chinese brand ones that appear on Amazon?!). I've been looking at used Maximus VII Heros that come up periodically on Ebay, and they can go for over £100. I could buy one in the hope that it would fix the above issue, but obviously if it's the CPU then I will be no better off. Even if it did fix the issue, this is still all old hardware, and I wonder how much time I might have left with it even if I got it working. Do you guys think it would be better to ditch the s1150 tech and buy a new s1151 motherboard/CPU combo as it would likely last longer? I've been looking at the Asus Prime Z390-P mobo and the i5 9600KF, which together come to £290 (so £190 more than a used s1150 mobo). Initially, I would be using the DDR3 2133 RAM and the GTX970, so still not latest tech, but don't think my 11 yo son would notice.