Burned out Mosfets

[woodsy61]

Hi guys I,m writing from down under & hoping u can help with a problem on my phantom 3 standard after having a crash on landing (after a lot of time money & testing) found out that i have burned out 3 of the 6-8 pin mosfets controlling one of the motors that won,t rev out . Could someone explain to me wot the series of numbers & letters represent on each mosfet, how to order replacements & from where . Thank,s for your time . woodsy61
P.S I have been quoted $300 to supply & resolder the 3 units in .

 

[Deleted member 120647]

Are they not the "name" of the device and possibly other 'details' too?
Any time I have tried googling such 'names' it has generally been successful though I might have had to google only sections of the 'name'

 

[NM_Quad]

I have not replaced the ESC mosfet chips in my P3S, but I did on my P2V+. I got the chips from Mouser Electronics in the states. Fairly common ICs that should be available at one of your electronic parts vendors down under. On the P2V+ they used IRF7425 (P-chan mosfet) and IRF7455 (N-chan mosfet) ... don't know about the P3 Phantoms. Seems I bought ten of them for less than $1 USD each (certainly not $300). The heat from a failed mosfet chip can weaken the PCB traces, causing them to lift slightly off the G-10 board material, so be very careful when removing the damaged chips to not break the traces. Use some solder-wick if you have to suck up the old solder or a solder-sucker with care. Any traces that have lifted off the board can be repaired with a drop of super glue and pressed back onto the board. If you know how to solder, soldering in the new surface mount chips is fairly easy. If you can't find the replacement part, post the numbers on the chips and I'll decode the part number, and often the equivalent from other vendors. Good luck with the repair.

 

[woodsy61]

Wow NM-Quad you really no your stuff & yes I was going to have a go at it myself but when u started talking about PCB traces breaking off & G-10 boards this project might be above my skill set,I,ll have to think about it . But if the chips r that sort of money I would appreciate if u could decode the numbers on them for me then at lest I,d no wot I was looking for . There r 3-8 pin chips that r bad but 2 r the same they r ( 1=4439,GMT,51616E) & (2 of 4439,GMT,51603E) Thanks NM-Quad for taking the time to sort this out for me . woodsy61

 

[NM_Quad]

I can not find any cross references for the numbers on your mosfet chips. They are likely "inhouse" numbers. Often a company (like DJI) will order thousands of a chip from an integrated circuit vendor and have them marked with their own "inhouse" numbers. These 8-pin mosfet chips generally have the same pin-out, but I hate to recommend a common device without knowing the pin-out for sure. Hopefully someone here has replaced them and can offer a proper consumer part number. I've had my P3S since they first came out, but have had no reason to open it up yet, thankfully. Good luck.

 

[Deleted member 120647]

Uum a question, does the entire chip number have to match? Just googling 4439 mosfet etc. turn up quite a few hits. Does the numbering beyond say 4439 indicate characteristics. I have never replace 'complicated' devices so please excuse me if I am asking a daft question or if it is badly phrased

 

[Zymurgist]

How about an image of the mosfet markings?

 

[NM_Quad]

As zymurgist says, an image would be helpful for the numbers and a possible logo identifying the vendor. Most pins on one side of the chip should be connected together and the same on the other side. There should be a single trace (the gate drive signal) going to just one pin. Knowing what pin number the gate signal goes to could also help. Both your N- and P-channel mosfets start with 4439, which may be a date code when it was manufactured, not the part number.