LED going bad (TWICE)

[ksrimoungchanh]

So, got WKM with F550 and FUTABA kit. Billowy 4S 4000mah battery.. fly for about 3 days.. seems to fly fine then, no Green LED during calibration.. What I was expecting was:

1. switch mode 8-10 times go get constant Blue for horizontal calibration.
2. turn on horizontal plane completely till it turns Green for the vertical plane calibration. Then wait for white.

I had the calibration turn Blue, but when I was expecting the GREEN, it was just off. I continued to calibrate the vertical as if it was GREEN and it completed with a white as expected. If flew normal.


I sent it back to reseller. Reseller said that they replace the LED and also installed/tested and sent it all back RTF.

everything flew great.. I normally do a GPS test, fly about 25ft off ground.. hover for a few minutes.. fly it upwind and hover, then power off TX to activate RTH.. I only have 2 batteries for now, and only run back and forth between the park and the house once a day.. so, first charge batteries is out at the park.. about 15miles away... then I come home charge for a 2 battery hover around in the yard. That is about all I get in a day's flying time.

About a week later, maybe 10 batteries.. (don't fly everyday), the BLUE LED indicators are not working. How I found out?

This afternoon, I took it to the park. powered on and waited for GPS purples.. normally about 1-2 mins or less, but this time, no purple.. I waited about 3 mins.. no purple. I powered of the WKM, and on, and waited again... and waited, and waited.. No purple.

So, I decided to calibrate.. in the process, I notice no BLUE. a ha!, purple probably needs BLUE and RED.. did the same as above.. continued anyway and the unit still fly as expected... Have not tried RTH, but have hover, and manually tried to move the hexa from it's hover and it goes back.

I don't think replacing the LED will be the solution alone. There is an underlying issue that I believe will cause a replacement LED to go faulty again.

Any input? my reseller had replace the LED the first time free for me.. assume it was under warranty. But now, they are reluctant.. I don't blame them, but I believe DJI or reseller should help investigate the true issue and resolve it under warranty. I think just replacing the LED was a good gesture and was the thing to do, but maybe was too soon to close the case.

Has anyone had this issue?

I am on 1.28.. that is what the reseller had it had. Don't want to start upgrading/downgrading etc.. without any finding first. Also when it still seems to hover nicely and seems to have a GPS without the purple indicators.

Could it be the PMU?
or could it be the WKM?

Thanks all.

KS

 

[ksrimoungchanh]

UPDATE: not sure the cause, but reseller told me that DJI wants the unit back and will send a new unit. will update, hope to get some technical info for readers to watch for, but dont hold breath.

Will probably just get a working unit and not know what the real issue was. Fine with me, but that would defeat the purpose of the posting.

 

[azure]

I don't know if it's a related issue, but I've had two NAZA LED V-Sens go bad for no reason so far. All functions seem okay, but no lights.

 

[ksrimoungchanh]

what did you end up doing? or did you just live with it? I use the GPS feature, about 70% of the time and the other is ATTI mode. so, I think the BLUE LED helps create that purple color to tell me GPS status so, it is helpful and I like that purple color..

Thanks for your input.

KS

 

[azure]

I just bought replacements. They are relatively inexpensive, and I didn't feel like having to deal with DJI to get exchanges and then dealing with the hassle of shipping.

 

[ksrimoungchanh]

I agree with you. I think, it is worth the try to work with DJI to exchange the WKM though.. especially if I am afraid that the effect was the LED going bad, not the problem. so, I am eager to find out what is causing 2 of my LED's to go bad and put that out.

I recall, my wife kept on replacing light bulbs in my guest bathroom.. I didn't keep track, but it started to seem like it was once every few weeks.. same light bulb.. we knew that light bulbs was rated at a certain hours and have expected life before replacement... but it seems much much too soon.. she replaced about 4-5 bulbs before we called in the electrician, to find the GFI had to be replaced.. Not sure how that was determine, but once we put a new GFI outlet in, which was sharing power to the light, we have not had to replace the bulb.

At 80.00 a pop on the LEDs, either go fly ATTI or Manual and forget GPS, or I should find that "electrician" @ DJI to help find that real issue to keep the LED from going out.

Has yours gone out anymore? how long as it been?

KS

 

[Bella7821]

I also had 2 WKM LED's go out.
If you push on the bulb very lightly you can get it to display different colors. I think what happens is when the bulb shell is pushed too hard (like if you have the LED mounted on your bottom plate and lay it on the table without legs) it will break it.
This happened to me twice with my S800, I had the LED mounted on the bottom plate and set it on the table without the gear or arms and then it stopped working.

 

[ksrimoungchanh]

Bella,

Bingo.. you are the best.. this is the first I have heard. I set to calibration where the blue was suppose to be.. then I lightly press on the rubber bubble.. till the blue lit up. It took a couple of bit to get the blue to stay lit.

Has yours come back off?

Regards,

KS

 

[Bella7821]

Bella,

Bingo.. you are the best.. this is the first I have heard. I set to calibration where the blue was suppose to be.. then I lightly press on the rubber bubble.. till the blue lit up. It took a couple of bit to get the blue to stay lit.

Has yours come back off?

Regards,

KS

I returned mine when my S800 crashed so don't know