400 series Roomba no power

Help & Support Domestic Robots
1

So I have a 400 and a 2.1 Roomba that both decided to stop working. I know the battery is good, as it works with my discovery. When I use the known good battery in either of the other two, they do nothing. No power on no beeps, nothing. If input it on the plug charger I will flash once and then nothing. They both screw up after I put in a rebuilt battery. So now I’m tryin to find what fried! Or is it better now to put in a new board? Or replace parts?
So what I’ve done

  • tried a good battery.
  • tested the charger
  • one Roomba is in parts now, and power goes up to U4 ( tested with meter) but nothing at U2. With a bad battery no power to either. ( charged still plugged in)
    -checked wiring up to the board

So I’m not afraid to test, or solder new parts into it. I will make one out of two if I can do that as well. Where do I go from here? What is my next step for testing purposes? As well where do I buy replacement parts?
Thanks for the help!

2

Sorry to hear that you are having problems with your robot. It does appear like the rebuilt battery has damaged your robots motherboards. We do recommend replacing the motherboard and not simply parts on the robots motherboard. The motherboard may not have apparent damage but, can still be defective.

We would suggest by starting with one replacement motherboard to see if it fixes the problem. We have discovery series motherboards available for sale. It will be compatible with your Roomba 2.1. We unfortunately do not have any Roomba 400 motherboards at the moment.

3

So it’s looking like I’m gonna need a new board now, what ever is at C31 has popped out if the solder joint. Can I just re-solder it back or is it now board replacement time? Or keep this one for parts, and tear the other one apart? Is it worth fixing it?

4

Upon taking the 2.1 apart it does not appear to have any issues on the board. Where do I go for testing on this one?
Thanks