COUT high means at least that the BQ is powered on, but DOUT low shows that it is considering that there is a fault in the discharge path, either a cell voltage under the UVP level or an overcurrent condition (OCD/SCD). I'd suggest probing directly on the BQ pins, to eliminate problems with the other components around the board. Check that the voltage between pins VSS (4) and BAT (5) is over UVP (2.8V for the BQ29700). Then with a scope probe the voltage on pins V- (6) on one channel and DOUT (3) on the other, using VSS (4) as common ground.
First connect the charger. The voltage on V- should become negative, and DOUT should become high. If DOUT stays low, check again the cell voltage, or whether there is a short between DOUT and ground somewhere. If there isn't any short I would start to doubt the BQ29700 itself.
With DOUT high, disconnect the charger and look at the two signals. While DOUT is high, the voltage on V- should always stay within the OCD/SDC window (for the BQ29700, below 0.5V after 250μs and below 0.1V after 20 ms). Of course once DOUT goes low the voltage on V- will go all the way up to BAT anyway. If the voltage on V- stays within the window and DOUT goes low anyway, then again I would suspect the BQ29700. If the voltage on V- exceeds the window then the BQ thinks there is an overcurrent protection. If the actual current on the load is not that high, then have a closer look to the MOSFets. It could be a bad soldering, or that they have a much higher RDSon than expected (wrong reference? fake parts?).
Oh and I almost forgot... before definitely suspecting the BQ29700, you can have a further test while probing with a scope the voltage between the BAT pin (5) and the cell positive terminal. It should always stay negligible. We had a prototype once where they mounted the wrong value for the series resistor on the supply pin, something like 10k instead of 100 ohms. The protection circuit would seem to work at first, but as soon as it tried to draw some current to change the state of a MOSFet its supply voltage would drop and cause all kind of weird problems. If the DOUT output is shorted to ground you would also see there an abnormal voltage drop there, due to high current consumption.
I don't really know what the pull downs would be for.
By the way is it truly a BQ29700, or another one in the BQ297xx family with different thresholds?
If you are suspecting the BQ29700, contact your local FAE, they can be helpful in finding the causes and have access to information and contacts at TI.