I have a similar issue to user Octo from the May 17 2020 thread "Tinyhawk 2: Is it bricked?" However, there are enough differences that I thought I would ask in a new thread.

After my Tinyhawk 2's moderate crash onto grass, FPV continued to work, but the FC would no longer boot correctly. When I plug in a battery to the FC, I get a partial boot: there are three beeps, followed by two blue lights, six green lights, and a red light. The light cycle repeats once, then all lights cease. The three beeps do not repeat. There is no additional sequence of beeps (as there would be during a full boot). Replacing fresh batteries does not change any of this.

Once the FC's partial boot is complete, the drone's rotors do not start. I cannot arm the drone. After a while, even FPV connectivity was lost and once lost could not be restored. Once FPV connectivity was lost, the headset just showed static. Replacing fresh batteries does not change any of this.

At one point, I plugged in a fresh battery and got the same partial boot (three beeps, light cycle, then nothing). But then, the rotors started to spin very, very slowly—perhaps 90 RPM (slow enough to track the individual blades by eye while they rotated). I was worried I might be causing damage, so I unplugged the battery from the FC. When I plugged a fresh battery into the FC, all I got was the same partial boot but no further movement in the rotors or any other component.

Plugging the FC into a computer via USB does not work. BFC does not recognize the FC as an FC once the FC is plugged into the computer. The computer does not appear to recognize the FC as a USB device. No lights or beeps come on the FC when I plug it in to the computer via USB. The FC is totally non-responsive to being plugged in via USB. It also does not work to hold down the FC's power button while plugging the FC into a computer via USB.

I unscrewed the FC to investigate. All components appear to be properly soldered into place. Like user Octo, there is a small, chipped component on the FC—in fact, the exact same damaged component Octo had on his FC. I will try to attach a picture below, with a yellow arrow pointing to the chipped component.

Any thoughts on what could be the matter?

   

Thanks,
Alex

That component looks like an inductor and it's just the ceramic casing that is chipped which won't affect the operation of it. From your description it sounds like you either have a fried voltage regulator or a dead MCU on the FC. Does the MCU get warm or hot when you connect power to the board?

(22-Aug-2020, 09:53 PM)SnowLeopardFPV Wrote: That component looks like an inductor and it's just the ceramic casing that is chipped which won't affect the operation of it. From your description it sounds like you either have a fried voltage regulator or a dead MCU on the FC. Does the MCU get warm or hot when you connect power to the board?

Hi SnowLeopard, thanks for your fast reply.

No part of the drone gets warm or hot when I connect power to the board.

Of note, when I plugged in a battery just now, the FC went through a full boot, except the beeps were slow and long-drawn out, not fast and crisp like a normal full boot. The rotors began whirling at a low RPM (90 rpm or so), then stopped.

Subsequent attempts to reboot the FC result only in the partial boot described in the original post: three beeps, light cycle, then nothing. The FC still cannot connect to the computer via USB.

Alex

With power disconnected, check for continuity between a 5V pad and a GND pad on the FC. Then with a LiPo connected, check what voltage you are getting on one of the 5V pads.

(22-Aug-2020, 10:57 PM)SnowLeopardFPV Wrote: With power disconnected, check for continuity between a 5V pad and a GND pad on the FC. Then with a LiPo connected, check what voltage you are getting on one of the 5V pads.

Uh-oh, we've now reached the (admittedly very short) limits of my technical competence. Thank you for your help, SnowLeopard, but it sounds like this project is beyond my capabilities. I had hoped the fix would be something simple, like "restart it with a 1S battery instead of a 2S" or something, but if I need to be tracing faulty circuits, then I'm afraid it's beyond me. Thanks for your help!

Alex

(23-Aug-2020, 02:46 AM)alexsidles Wrote: Uh-oh, we've now reached the (admittedly very short) limits of my technical competence. Thank you for your help, SnowLeopard, but it sounds like this project is beyond my capabilities. I had hoped the fix would be something simple, like "restart it with a 1S battery instead of a 2S" or something, but if I need to be tracing faulty circuits, then I'm afraid it's beyond me. Thanks for your help!

Alex

I have almost the exact same issue. Took a large fall after a building dive ( I blame IGOW2 week 4) Lost OSD, unable to connect via USB. When connecting battery I get this LED sequence: 3 Blue 6 Green 1 Red, it then repeats once. The same chip with the K on it is damaged, does anyone know what that chip does, and how can it be replaced?

(22-Aug-2020, 10:57 PM)SnowLeopardFPV Wrote: With power disconnected, check for continuity between a 5V pad and a GND pad on the FC. Then with a LiPo connected, check what voltage you are getting on one of the 5V pads.

I'm having the same issue, tested for continuity between 5V and GND, no issue there. when adding in the lipo, i'm not getting anything on the 5V pad and getting 5 on the 3.3V pad.

(24-Aug-2020, 03:05 PM)fritz Wrote: I'm having the same issue, tested for continuity between 5V and GND, no issue there. when adding in the lipo, i'm not getting anything on the 5V pad and getting 5 on the 3.3V pad.

If you're getting a 5V reading on the 3.3V pad then you must have fried component somewhere that has gone closed (or partially closed) circuit. The problem you have now is that the 3.3V rail also powers the MCU and the MCU doesn't tolerate a voltage above 3.6V, so if there is now 5V on the 3.3V rail then your MCU will almost certainly have been killed.

(24-Aug-2020, 03:16 PM)SnowLeopardFPV Wrote: If you're getting a 5V reading on the 3.3V pad then you must have fried component somewhere that has gone closed (or partially closed) circuit. The problem you have now is that the 3.3V rail also powers the MCU and the MCU doesn't tolerate a voltage above 3.6V, so if there is now 5V on the 3.3V rail then your MCU will almost certainly have been killed.

Hi! I'm having the same issue.
When I plugged in a battery, i have only 3 beeps with led (5 blue, 4 green, 1 red x 2). The FC cannot connect to computer via USB. There's video signal in the googles without telemetry.
I've tested for continuity between 5V and GND, no issue there. With the lipo, i'm getting anything 5,10 V on the 5V pad and 3.28V on the 3.3V pad. What could be the problem?

Thanks and happy new year!