Board fried while mod was connected to PC overnight

[Zakm0n]

One of my customers left her mod connected to a PC overnight, and woke up to a dead mod. the inside of the mod smells burned and when the lipo is connected to a good board on monitor mode, I'm seeing 2.45v/0.03v/2.31v. When the fried board is connected to USB, the area around the USB port gets hot. Fuse is fine, but otherwise, this thing is DEAD.

[VapingBad]

IIRC it balances by discharging the high cell across each of the 4 resistors near the USB and they could get hot especially doing it all night.  Was it on USB recovery charge mode as I didn't think it would attempt to charge cells as low as 0.03 V?

[Zakm0n]

No, it was just hooked up so she could play with the custom screens. No recovery charging or anything weird,

[Zakm0n]

Now my personal 2s 18650 mod is acting up. Lights up on USB and if you hold down the fire button but it says check battery. In monitor mode I'm seeing 0v/5.3v/0v and pack voltage matching cell 2. Also with batteries out I see about 3v on cell 2 and pack. Could this be the weird resistor issue I've seen crop up?

[soblue]

I'd recommend to any of your customers they not charge overnight and only charge while they can monitor the charging cycle.  I know I've read one of the admins state the board will not charge over 4.2V and that as the battery gets closer to full charge the charge rate is trickled lower so not to overcharge the battery pack.  But from personal experience I can say that's not always the case.  I've seen on a couple occasions (which I haven't been able to replicate) that the board was pulling close to 1 amp instead of the typical .5 amps or under when being charged through PC USB, while the battery pack was at or close to full charge.  Disconnecting the board and reconnecting it brought the charge back to the normal .5 amp or under in both situations.  I'm not sure what scenario causes this issue but since the DNA 200 board is in control of the charge rate I assume it has to do with some of the logic on the board.   I'm a bit concerned with this charging anomaly so whenever I charge I keep a close eye on the Charge, USB Current and USB Voltage.     

Attaching a screen capture of the second time this occurred.  Make note of each cell voltage of 4.2V,  USB Current at .956A & USB Voltage at 4.364V while the pack is practically full charged Pack at 12.59V.  Most of the time with a battery pack this fully charged I see the charge rate trickle down as expected and only see a few milliamps but not always in this example.  No idea why it was pulling 1 amp (twice what it normally is when connected to my PC) or why it hadn't trickled down when the cells were reaching 4.2 volts.  Possibly something similar happened to your customer and caused the issue while being charged unattended?
 

[Laminated]

I swap my DNA40 chip to a DNA200 chip on my Hana Mod DNA40vd. The mod hits like a champ but first time I attempted to plug the chip to my computer through USB sparks popped up around usb port on the dna200. I freaked out and unplugged the usb from the chip. No response from hitting the button plugging in the chip again the computer did not respond to it. I check all my solders and wires nothing was out of place or messy. The chip was fried... It was a great for the short time I had it...

[Spector NS5 RD]

throw up some pics of your build especially around the problem area, usb etc.