Hello guys!

I am trying to make my first 5inch 4s build (betaflight) and I think that I fried something. First of all the build includes the Kakute f7 v1.5 with the Tekko 32 f3 ESC stack, r9slim+.
The problem that I encounter is that when I plug the battery I hear the first pair of beeps and not the second pair, I connected the fc to my pc and in betaflight i see that the fc reads 5.5V instead of 16V. I read some threads and tried to flash new fw to the ESC but when I try to connect to blheli32 suite and it says "no valid ESC configuration".

Does anyone have any idea what is going on?

I have checked the batteries and they are fine
I tried different cable between the ESC and the FC and nothing
I disconnected everything and tried to power only the ESC and the FC and the problem persist
I checked for sort connections and there are none
I try to spin the motors and nothing
(the funny thing is that make a measurement with my multimeter in the Pins Vbat and ground and it is 5.5V, the Vbat pin is unfiltered so it should have been 16V)

Excuse my inexpirience but as I mentioned is my first build

When you get a 5.5V reading in Betaflight, is that with the LiPo plugged in? What LiPo are you using?

Did you check inside the ESC-to-FC harness sockets to see if there are any damaged or bent pins? Use a magnifying glass to do that if you need to.

Maybe it would be worth you posting a picture of the stack with the ESC-to-FC harness connected.

(16-Sep-2020, 05:37 PM)SnowLeopardFPV Wrote: When you get a 5.5V reading in Betaflight, is that with the LiPo plugged in? What LiPo are you using?

Did you check inside the ESC-to-FC harness sockets to see if there are any damaged or bent pins? Use a magnifying glass to do that if you need to.

Maybe it would be worth you posting a picture of the stack with the ESC-to-FC harness connected.

Thank you for your fast respond!

The 5.5V is with battery pluged in. the battery is LiPo tattu R-line 1550mAh
when the battery is unpluged it's close to 0
i checked the pins inside the sockets and all seems fine (I will try to upload an img but is a bit difficult)

I don't see any images. Please see the following post for how to upload some...

https://intofpv.com/t-how-to-upload-pictures

(16-Sep-2020, 05:55 PM)SnowLeopardFPV Wrote: I don't see any images. Please see the following post for how to upload some...

https://intofpv.com/t-how-to-upload-pictures

sorry about that, I try but it crashes
I sent you my dropbox link

https://www.dropbox.com/s/irbsy20cg7izzi...5.jpg?dl=0

https://www.dropbox.com/s/9y9abk6wajkw3o...2.jpg?dl=0

https://www.dropbox.com/s/dhqsgbpb3fnka6...4.jpg?dl=0

With the ESC-to-FC cable plugged in and also a LiPo connected, can you please measure what voltage you are getting on the back of the "B+" ESC socket pin on the Kakute F7 FC and also the "B+" pad on the other side of the board. The pins on the socket are quite small so be really careful you don't accidentally short the B+ pin to another one otherwise you might fry something.

(16-Sep-2020, 11:42 PM)SnowLeopardFPV Wrote: With the ESC-to-FC cable plugged in and also a LiPo connected, can you please measure what voltage you are getting on the back of the "B+" ESC socket pin on the Kakute F7 FC and also the "B+" pad on the other side of the board. The pins on the socket are quite small so be really careful you don't accidentally short the B+ pin to another one otherwise you might fry something.

Both pins are 5.5v when measuring with ground. If i try to measure the two B+ pins we will have fireworks! I also checked all the pins behind the sockets in Esc and fc to see if they are Indeed connected and they are! I start to believe that the problem is on the firmware side.

New Reply 

If you are only getting 5.5V on that B+ (VBAT) ESC connector pin when measuring with a multimeter (not using the Betaflight voltage reading) then the issue is either with the ESC-to-FC harness cable, or there is a hardware fault with the ESC because voltage from the LiPo is passed directly through to the FC on that pin. There is no firmware involved with that.

(17-Sep-2020, 09:31 AM)SnowLeopardFPV Wrote: If you are only getting 5.5V on that B+ (VBAT) ESC connector pin when measuring with a multimeter (not using the Betaflight voltage reading) then the issue is either with the ESC-to-FC harness cable, or there is a hardware fault with the ESC because voltage from the LiPo is passed directly through to the FC on that pin. There is no firmware involved with that.

sorry for being late! I ordered a new ESC (T-Motor velox) to test if it was a fault ESC and arrived today! it seems that the Tekko was damaged (kind of sad because I had high hopes for that one)! Thank you for your time and help!

No problem. I'm glad you found the cause of your issues even if it wasn't the outcome you were hoping for.