Need help identifying a 14 legged chip with no marking

[rddube]

Hello everyone,

I need help trying to diagnose the problem with this little board which controls the activation of a motor for a mini Liion powered chopping apparatus. The motor is rated 7.4 volts and should start when you power the power switch twice, but I only get a led flashing.

The chip I think may be at fault is the one pointed by the yellow arrow, but there no markings on it at all, nothing!

Any help would be appreciated. Many thanks!

[R_J]

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

Try cleaning the top of the ic with alcohol, it my revile a number. It might be a custom programmed chip

[rddube]

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

Hi R_J, I did clean it with alcohol but not luck, absolutely nothing.

[sam_sam_sam]

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

I am going ask a stupid question and I am not trying to be rude or mean but did charge the battery first even momentarily to activate the BMS protection board because a lot of devices have this requirement

Btw what is your battery voltage going to controller board

[stj]

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

you can try acetone if they painted it,
but i would check the other parts like the big transistors.

[rddube]

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

I am going ask a stupid question and I am not trying to be rude or mean but did charge the battery first even momentarily to activate the BMS protection board because a lot of devices have this requirement

Btw what is your battery voltage going to controller board

Hi Sam, yes I fully charged the batteries - my battery voltage going to the controller board is 8.4 volts. Tks!

[rddube]

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

you can try acetone if they painted it,
but i would check the other parts like the big transistors.

Hi stj, tried acetone no luck. I checked to big transistors and they seem to be fine. I think I checked almost every component on that board and they seem ok, just can't figure out what the pins of that big chip are.

When I press the start button (requires 2 quick presses) I only get the led to flash a few times...it flashes white. There is a wire connected from one side of the batteries to the board that plugs into a socket labelled VBM - if I disconnect that wire, and press the start button, the led flashes red. When I connect that wire the led flashes white??

Lost......

[R_J]

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

Have you checked the motor itself?

[rddube]

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

Have you checked the motor itself?

Yes I did check the motor and it is fine. stj put me on to something when he said "I would check to big transistors" and so I rechecked them, they are NCE2060K and sure enough, I think one of them is gone.

The good one, I get 273K ohms between ground and each leg, whereas the "bad one I think" I get 273K ohms on one leg and 8 megohms on the other leg, so I think it is open no?

I don't have this mosfet NCE2060K - it is rated Drain source voltage @ 20V and Gate Source voltage @ 12V. I do have some 70TO3GH that are the same N channel enhancement mode power mosfet, but the are rated Drain source voltage @ 30V and Gate Source voltage @ 20V - Do you think it would work if I change both mosfets? Thanks guys!

[R_J]

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

You can't check to ground because it will likely be different, check each mosfet by itself. What resistance do you get across where the motor connects? J2? this would check D2 to make sure its not shorted

[rddube]

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

You can't check to ground because it will likely be different, check each mosfet by itself. What resistance do you get across where the motor connects? J2? this would check D2 to make sure its not shorted

Ok, so I checked resistance between each leg on both mosfets, one of them I get 1K ohms, the other 8 megaohms.

Resistance where the motor connects is 395k ohms, same as D2 on one side, and D2 on the other side is 9k ohms.

What do you think?

[R_J]

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

Well Q3 has a 1k resistor R11 [102] across gate to source, I suspect Q2 does not. I suspect they are ok.
I see a regulator circuit next to L3 and although the picture is out of focus, R1 looks odd?

[rddube]

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

Sorry for the poor quality photos, here are better ones, both sides.

That regulator circuit is where the charging posts are on the other side of the board, I suspect it is for charging the batteries.

You can see on these photos where the switch to activate it is on the other side besides the led.

R1 looks ok it is written 101 and reads 100.5 ohms.

[rddube]

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

Just for the records and maybe to help diagnose, this thing stopped working when one of the 2 batteries completely died. They are 18353 3.7V Liion batteries, so I changed them and charged them before putting them back in and that's when it stopped working.

2 presses on the start button only gives a white led blinking 4-5 times.

Any ideas?

[stj]

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

maybe it's a fault code that got set and needs to be cleared somehow.

[rddube]

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

maybe it's a fault code that got set and needs to be cleared somehow.

Hi stj, I think you might be on to something, but I can't seem to find anything on the web - the brand of the machine is Home Exclusives.

I don't really see what type of chip could be holding a code , but maybe it's that long black 14 legged one.

I tried all sorts of combination with the power button, but haven't succeeded yet.

Any ideas are welcome and thanks stj!

[R_J]

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

What connects to +VBM? I can't really tell from the picture, but there looks like a solder bridge across the connections.

[rddube]

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

What connects to +VBM? I can't really tell from the picture, but there looks like a solder bridge across the connections.

Here's a photo of the connector which goes to one side of the battery. And yes, both posts of that connector are connected together but it's a single wire that connects in there.

When it is connected, and I try to start the motor, the led flashes white 4-5 times. When disconnected and I try to start the motor, the led flashes red 4-5 times.

[R_J]

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

Ok, I didn't know it was a single wire going there, so part of the circuit might operate off one cell, that's why the wire is connected in the middle of the two batteries. or they just monitor one cell when it is charging.

[sam_sam_sam]

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