Hey guys!
Today my cheapFOCer v2 stopped working flawless.
Vesc terminal prints the error “FAULT_CODE_HIGH_OFFSET_CURRENT_SENSOR_1” and neither Hall-Sensor detection nor Motor detection are working anylonger, so that the Motor does not spin at all anymore.
There was no incident or anything strinking.
I unpluged any cables, reinstalled 5.2 stable firmware, but the fault LED is still blinking and the error is still active.
Is there anything I can do?
Kind regards
Fisatec
Sounds like a cold solder joint on the drv current sensing input.
Thanks for your reply.
Unfortunately I don’t even know where this “drv current sensing input” is located.
Would it be hard to repair with basic soldering skills?
I buyed the cheap focer mostly assembled.
Kind regards
Fisatec
Check if pin 30 - 33 of the drv chip is connected to their respective shunts
That needs to be repaired, there is no way around it.
Luckily, there is someone in DE who can do that service, @seaborder, although I don’t know if this product has enough worth to make repair costs feasible.
Basic solder skills won’t do, as the pins are extremely small and there is a ground pad on the bottom of that IC you can’t see.
If the traces are blown off, there is a chance it’s not repairable. Can you send a high-resolution image of that spot, and check for any burn marks elsewhere on the entire PCB?
thanks brian, I have nothing to add to this 
@fisatec seems like one of the Current Sense Amplifiers, the DRV or something on the the way/lines
between those parts is broken or has bad connection
Thanks for your replies.
I will dismount the focer tomorrow and try to make some close ups.
Maybe this gives some more information.
Here are some close up pictures.
I removed the shrinking tube from battery and phase wires, so that you can see my soldering joints.
On fungineers discord-channel I was told, that bad connections of these battery and phase wires could have been the initiator.
@b264 there are no more burn marks on the PCB, but the traces are completely blown away.
Kind regards
Fisatec
This could be a cold solder joint
Great photos, I bet @seaborder can give you more information with these photos
Okay, thank you. I will definitely work on my soldering skills, so that this won’t happen again.
I am excited what @seaborder will tell about the pictures.
i think you shorted out the pins on the drv (Solderball etc.), those pins go directly to VSupply and GND, this created a bad short. The pads are gone but its fixable with a little bridge, also need to check shunt amplifiers and overall components
Got the exact same error, but my DRV nor PCB show any damage whatsoever…any clues as to what to replace?
check the 3 shunt amplifiers
I’m late to the party but to avoid any confusion…
The cheapFocer2 uses the 2 built in current amplifiers of the DRV8301 for phase 1 and 2. There is only 1 visible external Op-amp on the PCB sensing phase 3.
Fault on sensor 1 should indicate that something is not ok with the DRV itself (unless it is a continuity issue).
As @doomy said, pins 30-33 should be connected directly to the shunt resistors. Since these resistors are 1mohm, it will look like all these legs are connected together (which they are not!) in the cheapFocer2.
In other escs these legs are connected together to disable the internal shunt amplifiers (Schematic attatched by @seaborder) They all have 3 external amplifiers on the PCB. But not this esc.
I made an illustration how it looks
I have put plenty of km on my focers and to avoid DRVfaults, 65A Motor is the highest limit where I can run with zero faults. My opinion is to not go above.
nice, yeah that seems like the solution. 
I didnt know the internal shuntamps are used on this esc.
