Charging Failure 2012Leaf- replaced OBC, still not working.

Hi, I wanted to reach out to the community here and see if anyone has any suggestions what to try next to repair my 2012 Leaf.
Last week my leaf stopped charging with my lvl1 or 2 charger (Chademo works fine). Following the advise of several threads on this website, I checked the for a faulty diode- which was fine.
I then got a used but good condition OBC online (which costs a pretty penny) and tried replacing the front circuit board- the problem persisted.
I went ahead and pulled the whole system out and replaced it- unfortunately still no luck.
Finally I tried switching the front circuit boards one more time (so the new OBC was installed with the old circuit board)- but still nothing.
However I am receiving slightly different diagnostic codes with the new OBC installed.
At this point I'm at a loss and don't know what to try next. I haven't tried taking into Nissan yet out of concern for cost whether they will have an EV technician on site.
Any suggestions are VERY appreciated! Thanks in advance!

A few more details about the issue:
-original diagnostic codes: B29C1, P3173
-diagnostic codes with new OBC: B2840, P3173
-both units smelled the same- sort of chemically, though I am not familiar with burnt electrical smells.
-couldn't see any noticeable faults with either unit.
-When I plug the car in I hear the familiar cluck of the charge starting and it shuts down about 10 second after. The problem presented itself very suddenly without any prior warning that there was an issue.

The fault code of the "new" OBC has an indication of a fault on the power board or in the waffle plate with the high power transistors. It may have been damaged before you got it, and that may be why it was for sale.

Your original OBC codes reflect an issue with the EVSE such as discussed here:
https://mynissanleaf.com/viewtopic.php?f=30&t=32249#p605099

Does the car go to READY and you can drive it?

Did you take any pictures of the circuit boards and components while you had it open--there are folks here that might spot some damage that you didn't notice.

Thanks for your response nlspace!

The car does still go into ready mode and drives. It runs perfectly well except that it wont accept a charge. Here are just a couple of pictures I have of the original OBC's circuit boards.




The part is currently still uninstalled so I can get more pictures tomorrow. Ill also see if I can get any pictures of the "new" OBC that is installed. (I haven't put the back seat/cargo area together yet so it shouldn't be too difficult)

So, it is likely that I have 2 faulty OBC's on my hands rather than the issue being outside of the OBC- correct?

The images didn't show up here and the link goes to a sign-in at goggle, so couldn't see them.

Your original OBC codes were indicating a fault outside of the OBC--something wrong with the signals associated with the external EVSE charging device. The "new" OBC has a code for an internal fault in the high power section.

Following, I have a similar problem.