Need help identifying a 14 legged chip with no marking

[rddube]

Re: Need help identifying a 14 legged chip with no marking

This wire is one of the BMS protection board more than likely the BMS protection board might be having issues and that might be why one cell is bad I have seen this type of failure before

One other thing that might be going on is if the battery voltage on each cell is not close enough it can cause it not to work correctly

Make sure that the battery voltage between battery cells are as close as possible to each other one other thing to try is disconnected the battery cells and hook the positive and negative battery terminals first then hook up the center battery terminal sometimes this makes a difference sometimes it does not but it is a thing to try

Thanks Sam_Sam_Sam for your advice. Tried everything you mentionned, but still no luck. Should I maybe try to plug in the batteries reversed polarity? That might reset it, or could it just burn the whole thing up? Many thanks!

[sam_sam_sam]

Re: Need help identifying a 14 legged chip with no marking

No but what you can do put all three wires together for a little while and then re-hook the battery again this might work

[rddube]

Re: Need help identifying a 14 legged chip with no marking

No but what you can do put all three wires together for a little while and then re-hook the battery again this might work

Just to make sure I understand, you mean put the positive, negative wires of the battery together with the VBM wire? Won't that make sparks and heat up the batteries? Or maybe I didn't understand this right? Tks.

[R_J]

Re: Need help identifying a 14 legged chip with no marking

Just to make sure I understand, you mean put the positive, negative wires of the battery together with the VBM wire? Won't that make sparks and heat up the batteries? Or maybe I didn't understand this right? Tks.

I think he means short the Bat+, Bat- and +VBM connections together on the BOARD not the battery.

[sam_sam_sam]

Re: Need help identifying a 14 legged chip with no marking

I think he means short the Bat+, Bat- and +VBM connections together on the BOARD not the battery.

Yes this is correct that is what I was referring to

[rddube]

Re: Need help identifying a 14 legged chip with no marking

I unplug the battery before doing that, right?

[petehall347]

Re: Need help identifying a 14 legged chip with no marking

I unplug the battery before doing that, right?

yes correct or there will be sparks and smoke

[rddube]

Re: Need help identifying a 14 legged chip with no marking

Ok, unplugged the battery, put all 3 connections together B+, B- and +VBM for about 1 minute, reinstalled the battery and VBM wire, but same result...flashing white led 4 times.

[sam_sam_sam]

Re: Need help identifying a 14 legged chip with no marking

Then your BMS board has some type of issue which I can not give you any help with it other than the suction that I have already given you because I have not repaired them other than replacing the output transistors or mosfets but the ones that I have worked on you had some output and would drop as you it for a couple of minutes

[rddube]

Re: Need help identifying a 14 legged chip with no marking

Well thank you everyone for trying, I guess I will retire this one to the spare parts bin! Too bad, my wife really like this little chopper!

Thanks again!

[lotas]

Re: Need help identifying a 14 legged chip with no marking

I can’t say for sure, but maybe a current sensor is implemented in the circuit even when the current drops in the batteries (their wear)
The controller gives an error about replacing the batteries.

[rddube]

Re: Need help identifying a 14 legged chip with no marking

I can't say for sure, but maybe a current sensor is implemented in the circuit even when the current drops in the batteries (their wear)
The controller gives an error about replacing the batteries.

Did try to change both batteries with brand new ones that I know are good, but no go.

The yellow arrow in the photo points to a current sensing resistor - not too sure how to test that, but maybe that could be the culprit? I tested the motor and it runs just fine, no resistance at all!

[stj]

Re: Need help identifying a 14 legged chip with no marking

resolder the 3pin hall effect sensor

[R_J]

Re: Need help identifying a 14 legged chip with no marking

Are you testing this board in the unit or on the bench? if U4 is a hall effect, it may be there for safety and requires a magnet close to it to activate the circuit. What is the number on U4?

[rddube]

Re: Need help identifying a 14 legged chip with no marking

resolder the 3pin hall effect sensor

Not sure what a hall effect sensor is, but do you mean U3 ? Tks

[rddube]

Re: Need help identifying a 14 legged chip with no marking

Are you testing this board in the unit or on the bench? if U4 is a hall effect, it may be there for safety and requires a magnet close to it to activate the circuit. What is the number on U4?

I'm testing the board in the unit. I must be going blind, but I can't seem to locate U4 ? Help!

[lotas]

Re: Need help identifying a 14 legged chip with no marking

U4

[rddube]

Re: Need help identifying a 14 legged chip with no marking

Thank you Lotas. The marking on U4 is 4913B. Will try to resolder it and report back.

[R_J]

Re: Need help identifying a 14 legged chip with no marking

So it is a hall switch, check if there is a problem with whatever activates it, it might be a safety switch to prevent operation if a lid is not closed etc.

[rddube]

Re: Need help identifying a 14 legged chip with no marking

Eureka! Another nice ending story thanks to all of you! stj nailed it with the hall effect sensor (it wasn't the weldling) but what was activating it, which R_J confirmed afterwards.

I would have never known that that thing was activated by a magnet, and I guess when I opened the machine the magnet must have fallen out? When I put another magnet near that sensor, the processor started like a charm. So I used a fridge magnet, cut it up and inserted it in the processor and now it's purring like a cat!

Thank you to everyone who contributed to this success, without you I would have had to disappoint my wife, but now it's all cheers!

What a fantastic forum Badcaps is! THANK YOU!!