GL300B C1 briked

[gtboy]

P3P spent like 2 years on a shelf after being crashed. Got spare parts to fix it. Turned it on, DJI GO app installed on iPhone8 latest iOS. RC turned on, connected to the drone, entered camera view than it suggested to update RC firmware which I did. Seemed like successful, but after restart now is a constant beep and blinking red light. Tried all button combinations to reset it, relinked it to the AC. I can control the AC, start motors, but no camera view on the DJI GO app. iPhone doesn't see the RC and doesn't charge from it.

Tried Android device which is my old Samsung Galaxy S#somethig with Android 5.0 on it. The phone charges, but again, no camera view from the app. Tried to downgrade the firmware by pressing the academy sign on the right top corner for like 10 seconds, it says N/A, N/A, device disconnected, no firmware to downgrade, nothing in the drop down list.

Checked the boards inside for loose wires, blown or cracked smd components - all clear.
Checked voltage on the USB port, 5V for power and 0,8V for data line.
Used USB Device Info on the Android phone to check how the phone sees the RC:
Device Info
Device Path: /dev/bus/usb/002/002
Device Class: Use class information in the Interface Descriptors (0x0)
Vendor ID: 2ca3
Vendor Name (reported): DJI
Vendor Name (from DB): not found
Product ID: 1004
Product Name (reported): C1
Product Name (from DB): not found

Additional Info
Interface #0
Class: Vendor Specific (0xff)
Endpoint: #0
Address : 0x02 (000000010)
Number : 2
Direction : Outbound (0x0)
Type : Bulk (0x2)
Poll Interval : 0
Max Packet Size: 512
Attributes : 000000010
Endpoint: #1
Address : 0x86 (10000110)
Number : 6
Direction : Inbound (0x80)
Type : Bulk (0x2)
Poll Interval : 0
Max Packet Size: 512
Attributes : 000000010
Endpoint: #2
Address : 0x04 (0000000100)
Number : 4
Direction : Outbound (0x0)
Type : Bulk (0x2)
Poll Interval : 0
Max Packet Size: 512
Attributes : 000000010
Endpoint: #3
Address : 0x88 (10001000)
Number : 8
Direction : Inbound (0x80)
Type : Bulk (0x2)
Poll Interval : 0
Max Packet Size: 512
Attributes : 000000010

Seems like the Cypress chip on the main board works. At least it talks to the phone. I saw a user here @quaddamage already gave a lot of tech info on this forum. What direction should I dig next? Any suggestions are appreciated.

 

[Oso]

Plenty of posts that start with something like this:

P3P spent like 2 years on a shelf

Also include something like this:

I can control the AC, start motors, but no camera view on the DJI GO app.

Those two things go together often enough that @quaddamage put together the often referenced troubleshooting chart. Have you seen that yet?

Fix no video feed / black screen / no image transmission / no FPV on Ph3 Pro

Here you will find the diagram for diagnosing and fixing the most popular issue with Phantom 3 Professional. The solution will also work fine for Ph3 Advanced (though some branches are unreachable on this platform). Latest version is hosted here...

phantompilots.com

Introducing a significant change (FW update) makes troubleshooting more difficult. In case you’ve introduced a FW mismatch, do you know what FW you had on the RC and the AC before and after you made the changes?

 

[Oso]

iPhone doesn't see the RC and doesn't charge from it.
Tried Android device which is my old Samsung Galaxy something with Android 5.0 on it.

Not charging an iPhone is not unusual. Have you already tried switching cables? That’s a common problem.

With the Android device, have you already gone through the steps to set up Android devices?

 

[gtboy]

Have you seen that yet?

Fix no video feed / black screen / no image transmission / no FPV on Ph3 Pro

Here you will find the diagram for diagnosing and fixing the most popular issue with Phantom 3 Professional. The solution will also work fine for Ph3 Advanced (though some branches are unreachable on this platform). Latest version is hosted here...

phantompilots.com

Yes, I have. For my RC it's just a USB board replacement to check if it's OK for sure.

Introducing a significant change (FW update) makes troubleshooting more difficult. In case you’ve introduced a FW mismatch, do you know what FW you had on the RC and the AC before and after you made the changes?

I doubt it was a mismatch, the app suggested the firmware. I didn't update the AC, just RC via the DJI GO app. I don't remember the ver. on the RC.

 

[gtboy]

Not charging an iPhone is not unusual. Have you already tried switching cables? That’s a common problem.

Sure, 3 of them. No luck.

With the Android device, have you already gone through the steps to set up Android devices?

Not yet, but I will. Thanks.

 

[KachemakDiver]

It might be a mismatch now. Just one of the problems.
@Oso hit the nail on the head.

 

[gtboy]

With the Android device, have you already gone through the steps to set up Android devices?

Tried. No effect.

 

[gtboy]

It might be a mismatch now. Just one of the problems.
@Oso hit the nail on the head.

Even if it is a mismatch, I don't know how to fix this issue.