lol, now I have to scrape the old heat epoxy gunk off and put the heatsink back on. :)

Before I do this, is there anything else that anyone wants to see?

I thought the BEC would be in the middle layer, but that looks like the USB controller chip. Note the insulating white-ish material between the IC and the FET layer to keep the heat off the controller. I really think the BEC is made up of those two chips on the upper left corner of the first image above. I looked up the part number, and they are simply transistors. And looking at the traces, they are paralleled (bad idea for transistors IMO). I'll have to hook up the ESC and measure them to be sure. If those do make up the BEC, I might see if I can either heatsink them or remove them and squeeze in the ParkBEC I have. :)

They must be the BEC brian, they route directly to the red wire.

That's kinda what I was thinking, but paralleling transistors is not the best design, so I thought maybe they were for something else...

I'll do some playing around tomorrow (or I should say "later today" as it's now 2:22 AM) to be sure.

Who cares about time when you are on an important mission Brian..

Are you sure about part numbers? Looks like - 2 SOT-23 from LM2940 family of lowdropout regs...
Otherwise they just voltage followers but without matching currents with resistors in emmiters or growing them together would be not good (one will be always on vacation :) )

Serum: yeah really! Where are my priorities!? :)

Griffin: I couldn't find an exact part number match, but I did find a partial match and when I looked at the package, it was a transistor. So, I suppose I should have dug further. My bad. :dft001:. And even then, unless the LDO regulator IC specifically has FET outputs, you shouldn't parallel them. In this case, I wouldv'e used a pass transistor to boost the current.

HOWEVER! I did some testing that should really "put the nail in the coffin" for the argument to disable the ESC's BEC. Using several resistors, I hooked up a small 250mA load to the 5v output of the ESC BEC.

On 2s, the regulator circuit got warm, ~100*F, and seemed to hold that temp.
On 3s, the regulator circuit got very warm quickly to around 140*F within 20 seconds.
On 4s, the regulator circuit got very very warm very quickly to over 160*F within 20 seconds.

Don't forget, the MM uses the PCB traces as a heatsink. So, all that heat warming up all the surrounding components on the "brains" board. I don't what USB controller or motor controller ICs they use, but I highly doubt they are meant to handle that kind of heat. And these devices aren't even on a heatsink.

So, the lesson learned here is:

ANYTHING over 2s, use an external UBEC.

for those of you with ESC's taken apart. Has anyone considered stacking FET's to get more power and reliability out of thier esc. You would obviusly need a new case or at least modify the original to fit. A full set of double stacks should make things work much better. I had to do this on my mini-z. went from 2 FET's to 8. My punch went through the roof and it can now handle significantly heavier loads (bigger motor) and more voltage.

Yes, GriffinRU has said he has/can do this. Basically, unless you are running a hot setup, 100A and 4s is usually plenty. Most people would rather run higher voltage and less current.