Motors will not spin

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I have a Phantom 2 that I bought used – condition unknown.

I took it apart and checked for loose connections, damage, etc., and did not see any damage. I connected radio to the RC System Assistant and calibrated sticks. I connected P2 to Phantom Assistant and calibrated radio in this also. Radio appears to work and connect with P2.

I powered up P2, powered up RC and put the sticks in position to arm. Motors do not spin and lights flash red 4 times. I checked old posts and this is supposed to indicate there is no GPS. I checked the Upgrade tab and the GPS line shows all zeros in the Hardware ID and Firmware columns.

I purchase a used GPS module on Ebay, installed it, and there is no change in condition. I took the Ebay GPS module, put it on my working P2 and it works fine. I also checked the original GPS module on my working P2 and it works fine. It would seem the GPS module is not the problem.

I took the RC from my working P2, bound it to the problem P2 and there is no change - motors will not spin and lights flash red 4 times. I am looking for help, please.

I am including screen shots of the Basic RC tab and the Upgrade tab.

Thank you.
GPS 01102019.JPG
Transmitter 01102019.JPG
.
 
I have a Phantom 2 that I bought used – condition unknown.

I took it apart and checked for loose connections, damage, etc., and did not see any damage. I connected radio to the RC System Assistant and calibrated sticks. I connected P2 to Phantom Assistant and calibrated radio in this also. Radio appears to work and connect with P2.

I powered up P2, powered up RC and put the sticks in position to arm. Motors do not spin and lights flash red 4 times. I checked old posts and this is supposed to indicate there is no GPS. I checked the Upgrade tab and the GPS line shows all zeros in the Hardware ID and Firmware columns.

I purchase a used GPS module on Ebay, installed it, and there is no change in condition. I took the Ebay GPS module, put it on my working P2 and it works fine. I also checked the original GPS module on my working P2 and it works fine. It would seem the GPS module is not the problem.

I took the RC from my working P2, bound it to the problem P2 and there is no change - motors will not spin and lights flash red 4 times. I am looking for help, please.

I am including screen shots of the Basic RC tab and the Upgrade tab.

Thank you.
View attachment 107228View attachment 107229.

There possibly tthree answers as to why there's no GPS reading on the upgrades page. 1) No B+ pin 4 of the GPS socket. 2) broken traces of either pins 2 or 3 going to the CPU. 3) Open ground on pin 1.

By the way, the motherboard is two-sided. In the schematic, there are two checkpoints for pin 2 &3. Here are two schematics that should help you.
5 Volt supply.jpg
GPS & CPU.jpg
Upgrade Page_04.jpg


I have a bad habit of saving useful information and aren't you lucky I have such a habit. [url=http://www.desicomments.com/desi/smileys/][/URL]
 
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I have a Phantom 2 that I bought used – condition unknown.

I took it apart and checked for loose connections, damage, etc., and did not see any damage. I connected radio to the RC System Assistant and calibrated sticks. I connected P2 to Phantom Assistant and calibrated radio in this also. Radio appears to work and connect with P2.

I powered up P2, powered up RC and put the sticks in position to arm. Motors do not spin and lights flash red 4 times..

I had a similar in for repair, the main board was the issue, it just wouldnt see the GPS module.

other thing, the compass must plug into the GPS module if there is a socket for it, if not then it can be plugged into the motherboard, i tested this once with a Vision and it produced red light error

Im in the Uk if you need spares ive got some
edited
 
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There possibly tthree answers as to why there's no GPS reading on the upgrades page. 1) No B+ pin 4 of the GPS socket. 2) broken traces of either pins 2 or 3 going to the CPU. 3) Open ground on pin 1.

By the way, the motherboard is two-sided. In the schematic, there are two checkpoints for pin 2 &3. Here are two schematics that should help you.View attachment 107241View attachment 107242View attachment 107240

I have a bad habit of saving useful information and aren't you lucky I have such a habit.


Thank you for the reply - I was hoping to hear from you.

I have printed the schematics and will take the P2 apart after lunch.

I don't know what I am supposed to look at with the Upgrade screen shot. You have a red circle around Firmware for the gimbal which means?
 
Thank you for the reply - I was hoping to hear from you.

I have printed the schematics and will take the P2 apart after lunch.

I don't know what I am supposed to look at with the Upgrade screen shot. You have a red circle around Firmware for the gimbal which means?

The upgrade screenshot was just to show that there should have been a GPS reading but then it wasn't necessary since you have another unit to compare reading between the two units. I'm sure you'll have a use for the schematics.
 
Okay, I have the main board out and on the table (picture included here). I checked the GPS connector to ensure pins are seated - they are. I checked the GPS connector attached to the board for damage, i.e., bent pin, cracked, etc. - everything looks good. I turned the board over and looked for damage, burn marks, etc. - everything looks good.

There are no DJI stickers on the bottom of the drone (pic included here) - makes me think the body is a replacement and this isn't the first time drone has been apart/repaired.

So, there is a "DJI Phantom 2 Vision Central Circuit Board" on Ebay for $19.99

DJI Phantom 2 Vision Central Circuit Board / Part No.# 10 / BuyNOW~GetFAST 6958265109478 | eBay

Seems reasonable - my Phantom is a Standard - will Vision board work for me?



20190111_141423.jpg
20190111_141708.jpg
20190111_142122.jpg
 
I had a similar in for repair, the main board was the issue, it just wouldnt see the GPS module.

other thing, the grey wire compass must plug into the GPS module, the upgraded compass plugs into the motherboard, ive seen people swap the GPS for the one without the socket and try and plug the grey wire into the motherboard and it doesnt work.

Im in the Uk if you need spares ive got some

My setup is different - grey wire from compass connects on main board beside the GPS connector, not to the GPS module.
 
Okay, I have the main board out and on the table (picture included here). I checked the GPS connector to ensure pins are seated - they are. I checked the GPS connector attached to the board for damage, i.e., bent pin, cracked, etc. - everything looks good. I turned the board over and looked for damage, burn marks, etc. - everything looks good.

There are no DJI stickers on the bottom of the drone (pic included here) - makes me think the body is a replacement and this isn't the first time drone has been apart/repaired.

So, there is a "DJI Phantom 2 Vision Central Circuit Board" on Ebay for $19.99

DJI Phantom 2 Vision Central Circuit Board / Part No.# 10 / BuyNOW~GetFAST 6958265109478 | eBay

Seems reasonable - my Phantom is a Standard - will Vision board work for me?



View attachment 107250View attachment 107251View attachment 107252

I doubt you'll find a new board and of course, you have no idea what might be wrong with a pre-owned board. If I recall a new board was $49.00 from B&H when they were available in as late as 2016.

Do you have an OHM meter? I'd start by connecting the GPS module and battery to the main board and checking for B+ and ground connections before thinking of buying a board.
 
I doubt you'll find a new board and of course, you have no idea what might be wrong with a pre-owned board. If I recall a new board was $49.00 from B&H when they were available in as late as 2016.

Do you have an OHM meter? I'd start by connecting the GPS module and battery to the main board and checking for B+ and ground connections before thinking of buying a board.

I don't have an OHM meter (yet). I purchased a used board on eBay from a vendor that Mark the Droner has had good success with. I bought it using PayPal so if it doesn't work I will return. I am supposed to receive board by next Friday.

I read an old post from 2015 that talked about DJI solder joints and that you need to apply a lot of heat (60 to 100w) to break the solder joint free. Also, to be careful not to apply too much heat or you may lift the solder pad from the board.

Do you have any recommendations on working with DJI solder joints?
 
My setup is different - grey wire from compass connects on main board beside the GPS connector, not to the GPS module.

the grey compass cable must plug into the GPS module if it has the socket for it, if it doesnt have a socket for it then its fine to plug it into the board
 
I don't have an OHM meter (yet). I purchased a used board on eBay from a vendor that Mark the Droner has had good success with. I bought it using PayPal so if it doesn't work I will return. I am supposed to receive board by next Friday.

I read an old post from 2015 that talked about DJI solder joints and that you need to apply a lot of heat (60 to 100w) to break the solder joint free. Also, to be careful not to apply too much heat or you may lift the solder pad from the board.

Do you have any recommendations on working with DJI solder joints?

All the components on the board were connected with solder paste and hot air and if you apply to much heat with solder iron it can do more damage than good. Personally, I never used more than a 30 watt iron. To do a proper job of desoldering/soldering a Weller hot air station is what should be used but they are expensive for a small job. Tin lead solder will work but solder paste is a better choice to use.

the grey compass cable must plug into the GPS module if it has the socket for it, if it doesnt have a socket for it then its fine to plug it into the board[/QUOTE]

Your statement does not make a whole lot of sense ( marked in blue). To do a voltage or continuity check it is not necessary to plug in the GPS board.
 
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All the components on the board were connected with solder paste and hot air and if you apply to much heat with solder iron it can do more damage than good. Personally, I never used more than a 30 watt iron. To do a proper job of desoldering/soldering a Weller hot air station is what should be used but they are expensive for a small job. Tin lead solder will work but solder paste is a better choice to use.


In a working quad, the original GPs module had a socket for the compass to plug into

A later version of the GPS removed the socket

If there isn’t a socket on the GPS puck then the compass plugs into the mainboard.

If there is a socket on the GPS puck YOU must plug the compass into it otherwise you get a red light error as the quad doesn’t see the compass.

I wasn’t making the point to argue about any kind of checks or tests mate , just pointing out something that can cause the issue described
 
In a working quad, the original GPs module had a socket for the compass to plug into

A later version of the GPS removed the socket

If there isn’t a socket on the GPS puck then the compass plugs into the mainboard.

If there is a socket on the GPS puck YOU must plug the compass into it otherwise you get a red light error as the quad doesn’t see the compass.

I wasn’t making the point to argue about any kind of checks or tests mate , just pointing out something that can cause the issue described

While it is true there were two GPS boards available but the two socket boards were not used in P2 NV from 2014 on. Looking at the board in his photos there isn't a socket for a second cable coming from the GPS module.
 
While it is true there were two GPS boards available but the two socket boards were not used in P2 NV from 2014 on. Looking at the board in his photos there isn't a socket for a second cable coming from the GPS module.

Can’t see any picture of his GPS puck ?
 

The first thing I would do is to cut off that covering around the wires as it as metal threads woven into the cloth that can cause shorts on the board if it's laid across the components. My own didn't have that shield on the GPS cable and made no difference on sat signals. There may still be a photo of one that shorted out due to that shield in a post around 2015 from a friend in PA that I didn't save.
 
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I replaced the main board with a $18 Ebay board purchase today and I now have GPS and motors will spin up. (GPS module wiring does not have sheathing on it.) Connected Phantom 2 to Assistant software and I have a GPS line on Update page (which I didn't have before). I need to calibrate Phantom and then see how it flies.

Thank you for your help in this project. I'm encouraged that this Phantom will not be parted out and will fly once again.
 

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