OK, those logfiles show issues that were not present in the original.
In the first log, the encoder overloads almost immediately.
:36:07.820: [AMF] <Id: 5> Initial Frame Latency is 125734400 nanoseconds.
22:36:21.040: [AMF] <Id: 5> No output Packet, encoder is overloaded!
22:36:21.095: [AMF] <Id: 5> No output Packet, encoder is overloaded!
22:36:21.147: [AMF] <Id: 5> No output Packet, encoder is overloaded!
22:36:33.009: [AMF] <Id: 5> No output Packet, encoder is overloaded!
22:36:47.620: [AMF] <Id: 5> No output Packet, encoder is overloaded!
22:36:48.437: [AMF] <Id: 5> No output Packet, encoder is overloaded!
22:36:48.674: [AMF] <Id: 5> No output Packet, encoder is overloaded!
22:46:38.286: [AMF] <Id: 5> Input Queue is full, encoder is overloaded!
23:32:13.240: Output 'simple_file_output': Number of lagged frames due to rendering lag/stalls: 128699 (63.7%)
The same happens in the second log as well:
3:39:01.838: [ffmpeg muxer: 'simple_file_output'] Writing file 'F:/OBS/2019-12-29 13-38-58.mp4'...
13:39:19.862: [AMF] <Id: 5> No output Packet, encoder is overloaded!
14:44:03.882: Output 'simple_file_output': Number of lagged frames due to rendering lag/stalls: 171216 (73.1%)
14:44:04.174: ==== Recording Stop ================================================
14:44:07.583: Video stopped, number of skipped frames due to encoding lag: 106059/107046 (99.1%)
The GPU is overloaded attempting to render frames by a significant amount.
https://obsproject.com/wiki/GPU-overload-issues
23:32:18.642: Video stopped, number of skipped frames due to encoding lag: 117803/119666 (98.4%)
Your encoder is also completely overloaded, dropping nearly 100% of frames-- this is consistent with your statement that there's no video, but there is audio.
This indicates that whatever you're running and trying to capture with OBS is using so much GPU resources that there's virtually nothing left for OBS to use. Suggest shooting for 720p60 or 1080p30 and seeing if you have better luck there.