Phantom 2 fails to power up

[dougvg]

My Phantom 2 was working perfectly the last time I put it away, but now when I try to power it up (one push on the battery button, followed by another 2-second push), nothing happens. No sounds, no lights (except those on the back of the battery) -- nothing. I've tried several different fully-charged batteries, and none will power it up. I looked at the contacts on the batteries as well as in the Phantom, and all are bright, shiny, clean. It's as though the battery isn't connected to the Phantom at all. Is there a fuse inside the aircraft that would have this effect? Anything else I could try?

This is a Phantom 2 with maybe 20 hours of flight time on it, never had any problem starting it up before, no crashes.

 

[jason]

My Phantom 2 was working perfectly the last time I put it away, but now when I try to power it up (one push on the battery button, followed by another 2-second push), nothing happens. No sounds, no lights (except those on the back of the battery) -- nothing. I've tried several different fully-charged batteries, and none will power it up. I looked at the contacts on the batteries as well as in the Phantom, and all are bright, shiny, clean. It's as though the battery isn't connected to the Phantom at all. Is there a fuse inside the aircraft that would have this effect? Anything else I could try?

This is a Phantom 2 with maybe 20 hours of flight time on it, never had any problem starting it up before, no crashes.

To start the P2 one quick push of the battery button then push it a second time and hold. It shuts off with the same sequence.

 

[Great Pumpkin]

A good battery doesn't need to be in the Phantom to show its power level status. You ought to get green lights in the four slits to the left of the push button when you push that button twice. I used to push it three times until I found that two is enough.

 

[dougvg]

Thanks Jason,

I've started my Phantom 2 hundreds of times, using the method you describe. It just no longer works...

Pumpkin, I'm not trying to ascertain the battery level, I'm trying to start the 'copter.

 

[jason]

Thanks Jason,

I've started my Phantom 2 hundreds of times, using the method you describe. It just no longer works...

Pumpkin, I'm not trying to ascertain the battery level, I'm trying to start the 'copter.

Looks like you're going have to open up the shell. Have you a VOM to check voltages at two locations on the main board? There might be a cold solder connection on the power supply connection. Check the main supply than check the power going into a ESC module. If there's power at the ESC supply you have either a cold connection or a broken PS line

 

[CityZen]

The only likely cause that I can think of immediately is that one of the main battery wires has come loose from the main board. Or possibly there's a dead short somewhere.
This is because the ESCs are wired straight to the battery, and they would do something when getting power.

 

[dougvg]

Thanks Jason and CityZen,

As CityZen expected, there is a dead short across the red and black main power lines. I can see no loose wires, no wires touching anywhere. The ESCs all look good, and shaking wires and connectors on the main board doesn't affect the short. Does this mean that the short is on the main circuit board or should I be looking somewhere else?

 

[jason]

Thanks Jason and CityZen,

As CityZen expected, there is a dead short across the red and black main power lines. I can see no loose wires, no wires touching anywhere. The ESCs all look good, and shaking wires and connectors on the main board doesn't affect the short. Does this mean that the short is on the main circuit board or should I be looking somewhere else?

How do you know there's a dead short?

 

[CityZen]

Thanks Jason and CityZen,

As CityZen expected, there is a dead short across the red and black main power lines. I can see no loose wires, no wires touching anywhere. The ESCs all look good, and shaking wires and connectors on the main board doesn't affect the short. Does this mean that the short is on the main circuit board or should I be looking somewhere else?

I'd probably focus on the ESCs. Take a careful look at the FETs (the 6 identical large transistors) on each. There's a clearcoat over everything that makes it a bit difficult to tell, but look for any that might have a rippled surface or otherwise look suspect. Desolder one power lead of such an ESC and measure again the resistance across the battery terminals and see if you still have a short. If so, replace that ESC.

 

[jason]

My Phantom 2 was working perfectly the last time I put it away, but now when I try to power it up (one push on the battery button, followed by another 2-second push), nothing happens. No sounds, no lights (except those on the back of the battery) -- nothing.

Think about the statement you made hear." No sounds, no lights (except those on the back of the battery) -- nothing." Now if there was a short you'd one of two things happen smoke and no lights on the battery. If you are using a VOM and it has a continuity checker built in use it to find the open circuit. If a circuit or wire isn't open the checker will ring. So with the top shell off and the battery removed start with the battery terminals and check continuity each terminal to the power wires attached to the main board. If those are ok then start with the power supplies red lead and test each ESC + lead for continuity. Do the same for the negative lead.

Last of all. If you do not know what you're doing take it to someone who does. If you feel I'm a bit harsh that may true but fact is I have done this type of work for over 20 years so it doesn't hurt to learn from someone has done it for living.

 

[Mako79]

Does the battery turn on externally by it itself?

Only a suggestion...
Have you tried another battery other than your own? (could be battery firmware?).
Check the validation pins in the phantom.

Maybe try:
Force power the phantom...
Remove the battery, tap and long press to turn the battery on.
Now insert the battery in and see if the phantom powers up.

 

[edonovanl]

You might also give the battery terminals just inside the shell a quick clean...light sandpaper or a chemical cleaner like CAIG DeOxIT D100...