If you turn it on (cold boot) and enter the bios for a bit (give it a couple of minutes), exit without saving changes, and let it boot Windows, does it boot Windows successfully on the first try?

I tried the BIOS trick without success a few times. Last night just for the heck of it I hit pause during startup right after post, waited a few minutes, then hit the reset button and it started fine. But that was a first and I have to wait for a cold start to test if that trick works every time or if it was just a weird one-time fluke. The most frustrating part of figuring out this issue is that once it has been rebooted I have to wait a long time for it to have the same problem, and then I only get one chance to try something new.

Pretty much all Shuttle boxes up until the late, late Core 2 era suffer from bad capacitors. Given that, and the different behavior when it's warmed up, I'd suspect those first.

Remember to check the ones in the PSU as well. Those slimline power supplies have awful ventilation.
Also, keep in mind that OST caps (which Shuttle were inordinately fond of) don't always fail visibly.

Looks like Badcaps stocks a kit for your particular model, or at least the motherboard.

Rawrl wrote:

Looks like Badcaps stocks a kit for your particular model, or at least the motherboard.

😁 Oh man. Oh... oh dude.

So if badcaps stocks a pre-made recap kit for a system component you are having trouble with, you know things are bad. Ha!

Rawrl just about summed up my line of thinking.

Urgh. I was afraid it might be caps but hoping it wasn't as they look fine . . . such tiny, tiny capacitors on that board. I'm used to recapping compact mac boards, where when the capacitors fail, they all fail and leak goo. On the bright side, it looks like the badcaps kit only consists of the 11 bigger capacitors out of the 20 or so on the board. Maybe those the ones that tend to be an issue? I'm planning on replacing the PSU with something quieter anyways.

Also had to recap one of those with a pentium d processor. Went without trouble though. I just bought the caps from a local electronics store.

Edit: And yes, don't forget the PSU.

Rawrl wrote:

Pretty much all Shuttle boxes up until the late, late Core 2 era suffer from bad capacitors. Given that, and the different behav […]
Show full quote

Pretty much all Shuttle boxes up until the late, late Core 2 era suffer from bad capacitors. Given that, and the different behavior when it's warmed up, I'd suspect those first.

Remember to check the ones in the PSU as well. Those slimline power supplies have awful ventilation.
Also, keep in mind that OST caps (which Shuttle were inordinately fond of) don't always fail visibly.

Looks like Badcaps stocks a kit for your particular model, or at least the motherboard.

Not just bad capacitors, but a pretty tough life for caps in those Shuttle mini boxes.

So, a couple more tests and warming up the box by hitting pause before letting the system boot into windows, and that doesn't seem to help. I guess I'll look into changing the capacitors.

I still have a hint of doubt about capacitors being the cause though, as there are no random reboots, and this reboot problem is very predictable. It always happens only on the first boot into windows after the computer hasn't been used for a while, and it always happens immediately after the windows start-up sound finishes.

Maybe I should just try disabling the start-up sound...... 😜