I would also try an ethernet cable with only 2 pairs, 1,2 and 3,6, just to be sure that the POE thing is out of the equation for the moment.
None of the tests from the beginning of this thread have been with POE. POE works fine but I have been powering up with 3.3v only through the programming header with the bench power supply since it gives me more accurate readings on current draw.
The things that can draw more power are the drivers of TXP (LAN8710 pin29) and TXN (LAN8710 pin28), pins 1 and 2 of the RJ45. Check these, and check that the 50 Ohms resistors to VDD1A are in fact 50 Ohms.
Checked and still not seeing any shorts. I changed them (resistors) out with new as well, they are 51ohm as its the closest value I have on hand at the moment. Additionally I took a new unpopulated PCB and rechecked for continuity where it shouldn't be, no shorts.
May be the 8710 itself?
Swapped this out with a new one, did not have good pad connections probably for lack of solder paste. I put the old one back, got pad connections again and back to the same results. This leads into some theories below, I'm wondering if there's some bad PCB manufacturing issues contributing.
Are you still seeing the TXEN (LAN8710 pin21) pulses flat?
No! Kind of. I am consistently still getting a connection to the web if I plug and unplug the ethernet cable 6 times. 6 times exactly, every single time. Knowing this, the scope shots here are on the 6th connection. The pulses look healthy to me
when there is a connection to the web.
First set of packets:
![No ethernet PHY connectivity with ESP-32-WROOM 858224-0](https://www.eevblog.com/forum/index.php?action=dlattach;topic=212912.0;attach=858226;image)
Zoomed in on first pulse of first set of packets:
![No ethernet PHY connectivity with ESP-32-WROOM 858228-1](https://www.eevblog.com/forum/index.php?action=dlattach;topic=212912.0;attach=858230;image)
Second set of packets:
![No ethernet PHY connectivity with ESP-32-WROOM 858232-2](https://www.eevblog.com/forum/index.php?action=dlattach;topic=212912.0;attach=858234;image)
I'm beginning to wonder if the trace connections to the 8710a are causing problems. If you look within the orange boxes, it looks like their pad layout is shifted in the manufacturing from the PCB traces. Its all speculation at this point but possible the heating up is from degraded trace width and current capacity??
![No ethernet PHY connectivity with ESP-32-WROOM 858236-3](https://www.eevblog.com/forum/index.php?action=dlattach;topic=212912.0;attach=858238;image)
I have a bunch of microscope shots of a new, unpopulated board I am working on merging together in photoshop so you can see what I am working with, I will post an edit when it is completed.