Just to tell you about my experience. As now the P4 is here, that's time for me to decide for either plan to upgrade to P4 or buy spares for the P3 waiting for P5 or P6. I have gone personally to keep P3 as I don't see big useful to me improvement in P4 and I would have a lot to invest in buying new spares and accessories (batteries, charger hub, charger, spares ...). So after checking my stock, I come to the conclusion that I need a spare ESC board Part #33 as I have already a set of old motors and 2 shells (I have already a small crack ). It seems to me that it becomes not that easy to found; having DJI telling you they don't ship such spares to your country doesn't help you having a good feeling for the future. I found a good supplier on Ebay (DJI Phantom, Helicopter items in Walkera store on eBay!) for the ESC board Part #33 at a very good price. Item description/picture was showing the same board and components as on mine. So big smile, I ordered it. I received the time and the package was labeled with what was looking as issued by DJI as Part #33. In the package, there was a new PCB nicely packed and nice paper about the 2 different versions of the board old for motor 2312 or new V2 for motor 2312A. Sorry a poor copy is bellow. It says that there is a label with number 44*A for old or 44*B for the new version. I of coarse (Murphy law) received a part labeled 44*C After some search on the internet I tried to compare the components on the board, there was a coil that was the same as a 44*B version. Here a sample of what can be found on Ebay: It shows a component as a difference between the 2 versions with only A and B version of the board. Mine had the "new" board component but a C version . So I thought I get an ESC board Part #96 and started a return process with the seller. By chance, I thought I should try to see on our nice forum if there is something about that subject. Not that easy to formulate the right search string but I finally found that thread where the OP had the same issue: Professional - P3P main board replacement was supposed to be part 33, doesn't match Thankfully to the OP, he solved it on his own (asking DJI and trying by himself) and reported back his solution. This confirmed me that the Part was really an old ESC board #33 "compatible" and I was able to close return on Ebay. In fact it seems that DJI reproduced a modified version of the ESC board to support the old motor, wich is good from them. The bad is that there are no mention of it by DJI. The seller of that board was nicely supporting me and I was able to start a return through his support and finally cancel it after I found the related thread. Maybe it would be good to have such kind of information related to compatibility of ESC boards / motors on our valuable information ressource at DJI Phantom Accessories & Tips - Phantom Help Best would be a full confirmation from DJI. Again a big thanks to all the peoples that give feedback when they found solution to their problem, that's one of the key point of a forum.