Been flying my tinyhawk 2 about a week.  This is my first 'real' quad and first FPV.  Been some crashes, but nothing crazy.  Mostly flying over grass.

Just picked it up and the flight controller won't boot.  Won't connect to Betaflight Configurator even with boot button held as i plug in - (found that tip here).  I can see a chipped component (inductor?) on the board, see https://imgur.com/a/WZZVVoL  .   Also some green (grass residue) on board - should i try to alchohol clean it?  Any voltages to check?

Thanks for any help.

Doesn't hurt to clean your FC. But the FC not booting is not good news. Especially if you are using USB.

Do you have any led light up with USB or lipo?

(17-May-2020, 08:20 PM)voodoo614 Wrote: Doesn't hurt to clean your FC. But the FC not booting is not good news. Especially if you are using USB.

Do you have any led light up with USB or lipo?

No LED with USB.  The VTX flashes the channel and works on lipo but no OSD.  Was just double checking and if i wiggle the USB on the way out the main board red LED will light (as long as i hold the USB in 'just the right' angle.  Also heard the CPU register/deregister a new USB, but can't even get that to happen again.

Any ideas on that component?  I can see little windings in there so i assume it's an inductor?

Thanks for the response.

The inductor is probably fine. It is usually for filtering. As long as the winding is not damaged, you should be fine.

Sounds like you might have issues with the USB port. And also I think one or both of your regulators is dead. Let me see if I can find out where they are.

I see that you have 5V pad on the FC. Plug in lipo and check both the 5V and 3.3V. Don't use buz- as ground. Find another ground. Unfortunately since your USB is not reliable, we cannot for sure rule out that the 3.3V is bad. Otherwise I would ask you to plug in USB and check the 3.3V.

One side of the bind switch was shorted to the negative pole of the battery. I used that side of the bind switch and measured 5.0 V on the circular pad at the bottom of my picture and 3.3 V on the capacitor marked on the bottom with a lipo attached. Bought a new board so microsoldering is in my future but still open to any debug ideas.

So your regulators work if I am reading you correctly.

Maybe check the solder on the USB port. Maybe you can get onto BFC and see what is going on. A complete reflash might solve the problem.

Inspected the board more closely and there was some gunk between the motor pads. Scraped it clean with a needle and connected lipo. It booted up and light was on and FPV showed OSD! Then tried on USB - nothing. on lipo - nothing. So seems like somethings shorted intermittently? which of the three motor pads should be shorted together (if any - and with both motor and ESC attached?)

Also it does beep three times three tones when lipo attached - I read somewhere there was no buzzer so the beeps were motors - does that mean the motors/esc is 'working' - that i get tones? That and the VTX is pretty consistent. The boot definitely not. Do you have cleaning tips? I used IPA and a q-tip. This was a bad idea as now there's cotton everywhere. Then i went over it with IPA and a toothbrush. Is IPA residue problematic?

Thanks so much for your ideas.

Three beepers mean esc are working.

can ESC work without flight computer? Doesn't the FC have to prompt the ESCs to make those tones - or can they 'boot' with those tones independently?

Worked on it a bit more - i might be getting old or used to nice binocular microscope at work but tough to see gap between the motor pads. Anyway I finally got it to connect to CPU and stay long enough to dump and status. When first entering CLI i see: M>lj before it spits out the 'Entering CLI Mode....'

Status is:
# status
MCU F411 Clock=96MHz (PLLP-HSE), Vref=3.24V, Core temp=39degC
Stack size: 2048, Stack address: 0x2001fff0
Config size: 3757, Max available config: 16384

System Uptime: 227 seconds, Current Time: 2020-05-19T03:16:00.426+00:00
CPU:2%, cycle time: 0, GYRO rate: 0, RX rate: 111, System rate: 9
Voltage: 831 * 0.01V (2S battery - OK)
I2C Errors: 0
SD card: Not configured
Arming disable flags: NOGYRO CLI MSP

CLI and MSP seem ok - NOGYRO is concerning.
Also - the voltage seems strange (8.31 V when on USB only). It seems like when i had it on a 1s lipo (around 3.8 charged) the OSD was showing >7V at one point but won't swear to that.

New ideas?

The suggestion for NOGYRO is to reflash or get everything back to default using the "default" CLI. Make sure you back up prior. See if the problem goes away or stay. If you still have the problem, then you have a hardware problem. People recommend reflowong the gyro chip. Hot air gun or hot plate.