JEB123
05-20-2008, 04:24 PM
If you smoked a 3 in 1 on your Axe CP by having the ground stop the blades or anything that stopped the motor suddenly, this may solve your problem. I found two things wrong with my board, yours may have more problems. From what I have seen, the board uses one CX1024 adjustable low dropout regulator for the BEC and to power the Rx. This is the large square IC on the side of the board with the trimmers. Next to this large IC you'll see two yellow capacitors, a large and a small one, marked 476C. Right next to them along the edge of the board there is a copper ground trace filled with vias (holes) that act like a fuse. I found this trace burned open. Solder a piece of wire across there to repair the circuit. On the other side of the board there are three 9926B dual power MOSFETs (8 pin chips). Of the six MOSFETs, 5 drive the main motor and 1 drives the tail.You'll see the three IC's in a row on this side of the board. Between these IC's and the edge of the board with the wires you'll see two diodes that look like black squares with the words "tail" and "main" silk screened next to them. These are SS14 schottky diodes. Diodes are polarized and can only be installed one way.
On my board, one of them was shorted. It is best to just replace both of them.Note that the cathode (a faint white line on one side of each chip) faces the center, the two lines on the diodes face each other. If installed backwards the circuit will not work. This diode is available from DIGI-KEY.com, part no SS14CT-ND for 36 cents.The only problem is they have a minimum order. You could sub any 1Amp 40 V or more rectifier diode, it is just for reverse polarity protection. These two things fixed mine, I hope it fixes your 3 in 1.:thumbup:
On my board, one of them was shorted. It is best to just replace both of them.Note that the cathode (a faint white line on one side of each chip) faces the center, the two lines on the diodes face each other. If installed backwards the circuit will not work. This diode is available from DIGI-KEY.com, part no SS14CT-ND for 36 cents.The only problem is they have a minimum order. You could sub any 1Amp 40 V or more rectifier diode, it is just for reverse polarity protection. These two things fixed mine, I hope it fixes your 3 in 1.:thumbup: