GL300E Troubleshooting, wont start.

[AussieRaff]

Hi Everyone,

Recently I pulled my Phantom 4 Pro Plus out for a fly. It'd been in storage for about 2 months.

The Drone itself seems fine, but the controller has an issue.

It wont power on.

If I press the power button all battery level leds light and the thing beeps at me. the usual press then press again to power on doesn't work.

I tried charging it with the standard charger, it makes a faint beeping sound but no leds light.

I checked the internal battery, its at 8.4 volts, so should be charged.

I read somewhere that holding down C1, the shutter button, then the power button might help, that forces it to power on, but without the ability to connect to the drone, and it seems to force a firmware update, then powers off, back to square 1.

Firmware was up to date before storage and everything was fine.

Spoke to DJI Australia, not much help there.

Any ideas?

Thanks,
Raff

 

[Capt KO]

I saw that happen once and it turned out to be the screen was set too dark to see. Can't remember the trick to lighten it up. Try going into a dark closet and see if you can read the screen. Believe it's adjusted in the drawdown (finger from the top) screen. Maybe Google/youtube can help with that.

 

[Capt KO]

Did it work? Let us know how you fixed the issue to help others, teaching/learning is what this forum is good at.

 

[nahacar]

A few things you can try:

Even if it shows ~8.4V, the controller’s battery management can get stuck. Try leaving it on charge for several hours (even overnight), or let it sit unplugged until it fully drains, then recharge again. Sometimes it won’t boot if it isn’t getting proper input current, even if it "looks" charged.

Force reboot combo - hold Power + C1 + C2 + Shutter for ~10–15 seconds. This can reset the controller logic.

Since you opened it, make sure the connector is firmly seated and no voltage drop occurs under load.

If it still only beeps with all LEDs lighting, it’s often a power board or BMS issue, not the cells themselves. In that case, repair or replacement is usually the only fix.

 

[sileye]

If it won’t start at all, double check the battery contact pins and make sure the battery is fully seated. Sometimes the connectors get a little worn or dirty and prevent proper power. Also try a different battery if you have one. If it still doesn’t power on, it could be a contact issue inside the unit.

 

[AussieRaff]

Thanks for the replies.

I have tried seeing if the screen brightness is all the way down. No, that's not it. I doesn't actually power on at all.

I tried the suggested Force Reboot combo, it cycles the battery level leds and faintly beeps about once a second, but doesn't power on.

Im going to try powering it from my bench power supply next when I get a chance, I will report back how I get on.

Thanks all!

Raff

 

[AussieRaff]

Hi everyone,

An update to my issue with the GL300E controller.

Tried powering it with my bench supply set to 8,6 volts, about 150mA current draw, but the same problem, doesn't start up.

Tried heating a few small chips near the battery input connector as Ive read that there is a chip there that might be responsible for my trouble and heating it might help.

Long story short, I isolated it to a chip near the beeper on the board, its tiny and has 8 pins, and is marked PA 7B5 or PA 7BE hard to see as it was covered with some waterproofing goop. Its about 2mm square.

I tried resoldering it with flux and hot air, that got it working for a short time, but then as it cooled, back to not working.

I'm pretty sure the chip is faulty.

Anyone have an idea what the chip is so I can source a replacement?

I drew a blank looking on google, but I suspect its either the charge controller / fuel gauge chip or a dc to dc converter chip.


Regards, Raff

 

[crash1sttime]

I drew a blank looking on google


Regards, Raff

I think DJI have a habit of using chips that cant be identified to prevent reverse engineering of products