balance issues

[jopatken1]

I have a dna 200 that im having power issues with. The chip powers up fine and connects to escribe fine but will not vape battery meter is empty and percentage says zero. In the device monitor i have my number one cell that says 1.85 volts and number two and three are sitting at 3.85 volts and the same thing is happening with two batteries i thought my first battery went dead so i bought a new one and same thing dead cell, it says.

[BJ43]

Have you tried jump starting the low cell. If you do not know how, find a RCer to help you. Escribe has a program to jump start a bad cell but it did not work on two of mine. Still had to do it the old fashion way. Test the cells with a meter and see if you really have a low cell. Balancing chargers will not start charging if one cell is below minimums. To jump start you have to hit that individual cell with a 3.7v charge for about 10 minutes to bring it up over minimum and then the balancing charger will recognize it.

[jopatken1]

My problem is im stuck at a childrens hospital without my meter but three batteries now all say number one cell is low i find that very odd when you did it how low was your one cell if its number one cell what wires on balance connector do i use

[jopatken1]

mind you two of the batteries were brand new

[Dampmaskin]

I'm thinking there must be something wrong with either the wiring or the board. Three different batteries don't just fail in the exact same way by chance.

[RickAdair]

Most likely a short in the balance connector wired to the board or one of the resistors is missing/damaged.

[jopatken1]

Ya the guy who built it said he believes it's a resistor I don't know what to do about that

[James]

Has cell 1 ever read properly?
If not, how did the mod pass through Production Utility? (Did the mod maker not use it?)

[blueridgedog]

Symptoms seem similar to mis-wired balance taps.

[Flavored]

Exact same issue on one I wired up this evening.  Cell 1 at 1.85 V, Cells 2 and 3 at 3.7.  I soldered the balance wires directly to the board, no room for the connector in that BRD squonker.  After I had it all done, hooked it up to Escribe and upgraded firmware, then looked at the monitor.  Battery pack indicating 9.3 volts.  So I unplugged it and took it back to the soldering station and hit each spot with the iron again holding the wire down with one of the tools.  Hooked it back up, still the same.  One more try adding a spot of solder to the #1 spot on the back side, no change.  Oh, and I metered it in between the solder jobs and have a nice 3.7V on all three cells and 11.1 for the pack each time, front and back (ie - the pads, not the wires from the battery).  Think there's an issue with the metering on the board, seeking guidance.

[VapingBad]

Check the 4 resistors near the USB socket undamaged

[Flavored]

These microscopic things on the right?

 

Or these microscopic things on the left?

 

Or these microscopic things on the back of the USB (and above)?

 

If I had to guess, that one on top of the first pic doesn't appear to be properly attached.

[Mad Scientist]

Flavored said:

These microscopic things on the right?

 

Or these microscopic things on the left?

 

Or these microscopic things on the back of the USB (and above)?

 

If I had to guess, that one on top of the first pic doesn't appear to be properly attached.

I think you guessed right. You definitely seem to have detached a resistor. Also, the ground wire on the balance pad looks to have a stray strand sticking out. Doesn't seem to be touching anything else but needs to be cleaned up so it never does. The photo isn't clear enough to tell for sure but you might be able to reflow the torn resistor back to the pads. OTOH, if a trace is damaged, the board is likely done.

[VapingBad]

That's it, the top pic you can see the tracks coming from the balance socket and that outer/top resistor one could be the problem.  BTW looks like a stray strand of copper on the black balance wire in top pic I would trim IIWU, although it is only ground so shouldn't be a problem.

[Flavored]

Amazing what a magnifier on an iPhone can do, that strand didn't show to my naked eye. 

I'll examine that board more closely with a real magnifying glass tomorrow, then see if I think I can get my fine point tip on it with a little drip of solder.  Thanks for the input!

[Willy]

Also looks like a bead of solder on that resistor

   

[Flavored]

I think that is a reflection, but I'll check.  All soldering was done on the other side.

[Flavored]

And, notta chance I'm gonna poke that with a hot metal stick with a glob of conductive material on the end with a power source connected.  And if I'm gonna carefully disconnect said power source, I think I'll just ask for RMA.  Thanks for the help!