I experience the same problems as @aoe2exp has described above, while using a different setup. I'll try to make it as clear as possible:
After playing approx. 10 minutes, the eGPU suddenly shuts off, leaving either a black or blue screen of death.
Observing the eGPU socket, the problem occurring looks like this [10 secs video] while playing a game:
For anyone interested, here are some GPU-Z logs of these crashes:
Laptop: Sony Vaio VPCSB2C5E
OS: Windows 10 (x64) (freshly installed)
CPU: Intel i5-2520M @ 2.50GHz 2.50GHz
RAM: 6 GB
iGPU: Intel HD 3000
dGPU: AMD Radeon HD 7400M
eGPU: Nvidia GTX 770 with driver 372.70; PCI Express x1 Gen 2; has one 6-pin and one 8-pin contact;
Board: PE4C v3.0 via mini PCI-E (removed Wi-Fi card)
PSU: Xilence XP400R6
Unused PSU Cables
Setup 1.3 (thank you @Tech Inferno Fan)
GPU-Z for GTX 770
Multiple re-installs of OS and drivers (also via DDU and in safe mode) (problem persists)
Test of possible driver combinations (Intel/Nvidia, Intel/AMD/Nvidia, only Nvidia drivers installed) (problem persists)
Tried changing from Gen2 to Gen1 (problem remains, while eGPU performance decreased) (problem persists)
Isolated PSU (problem persists)
Tried different chainloader modes (problem persists)
Tried replacing the 6-pin cable (from PE4C to GTX770) with the 6-pin cable from PSU (to GTX770) (problem persists)
Tried different games (problem persists)
Tried PE4C v3.0's "Force Power On" bypass (problem persists)
Tried hot-plugging (card cannot be used and fans spin on full blast, card works when plugged in when booting)
Replace the PSU with a more powerful one?
I've read about fuse bypassing here (though for PE4H) - could that be a possibility?
Many thank's in advance!