system sometimes hangs at startup (Elite 8300 MT - QV994AV)

[BillHolland]

I recently upgraded my Elite 8300 (QV994AV) with a fast GPU (NVIDIA GeForce GTX 1650) and additional memory (32GB). Especially the GPU is gives a huge performance gain in image and video editing. The problem I now occasionally experience is that the PC does not want to boot and hangs even before showing the BIOS splash screen. Previously I never had this problem despite having used the PC extensively for years.

Normally the startup goes like this:

- I press the powerswitch

- the power in the system comes up and the DVD player initializes itself.

- after about 10 seconds the speed of the fan in the power supply drops (was not very high anyway)

- the monitor turns on (comes out of sleep mode)

- the BIOS splash screen appears on the monitor

- and immediately after that, Windows boots up

But sometimes the PC does not start up and it goes wrong like this

- I press the powerswitch

- the power in the system comes up and the DVD player initializes itself.

- the speed of the fan in the power supply does NOT go down (is not very high anyway)

- the system hangs

- after about half a minute the speed of the fan in the power supply increases dramatically, the power supply starts blowing.

- then I had to unplug the mains because the PC stopped responding to the power button.

The question is what is going on here. I first replaced the video card with the old one, that did not solve the problem.  It seems to have something to do with memory. Because if I replace all the four units (4 * 8 GB) with the units that were originally in it (4 * 2 GB), the problem is over. I do then have to press (F1) at startup because the size of the memory has changed. But if I then replace all 4 * 2 GB modules again for the new 4 * 8 GB modules, the problem is also over. I do then have to press (F1) again at startup because the size of the memory has changed. Incidentally, partially removing the 4 modules (leaving 2 * 8 GB) did not solve the problem either. Also not when changing strips white/white to black/black. Those new modules really needed to be taken out and temporarily replaced with at least 2 of the original modules.

To rule out an error in one of the new 8GB memory modules, I had Memtest86 do a complete memory test (which took eighteen and a half hours) but no errors were found.

Seems to remain that either the modules are not 100% compatible with the motherboard (they are G.Skill DDR3-1600 F3-1600C11D-16GNT) or the BIOS has an issue with these modules. I've just updated the BIOS from K01 v02.05 to K01 v03.08 (via an intermediate step on K01 v02.99) and so now it's just a wait and see.

Since the problem occurs only rarely (In the three weeks I have been using the new memory modules  the issue occurs 2 times while the PC is used at least 5 hours every day) the question is whether the problem is now solved.

What other cause could there be?

[BillHolland]

Below is additional information about the new memory modules

[BillHolland]

The problem seems solved by the BIOS update from K01 v02.05 to K01 v03.08 (via an intermediate step on K01 v02.99). I haven't had any issues since then.