Roomba 4220 light says charged but wont turn on

How long is it charging until the light goes from flashing red (no charge) to yellow to finally green (full charge) ? If it's not at least 2 hours, sorry I don't have my Roomba papers available, so I'm guesstimating here, it's not getting a full charge. If you can put a voltmeter on the " fully charged" battery pack, that might tell you if the charger is the problem. Clean off the metal contacts where Roomba meets the two metal contacts on the charger. Also just because a battery pack or set is new doesn't mean it's functional. I had a new Apple battery for my laptop that didn't work when I replaced an older one.

Bad PC board. Throw it away. Robot vacs are nothing more than novelties ( expensive toys ) They may do what you want them to do at first but they never last very long and other than brush replacements they are not repairable. If it is within the warranty period you can get a replacement with that.

The color flashing tells you how close you are to a full charge. The orange/red flashing should change to yellow and finally green. Sorry I have an original model so your's might be slightly different. Does it never change from orange/red?

"The Charge Indicator Light is located immediately to the right of the power button on Roomba Red and Roomba (sage). On Roomba Discovery and Discovery SE, the Charge Indicator Light is incorporated into the power button. Please refer to the table below to determine what the Charge Indicator Light is telling you.

* Pulsing Amber - Charging
* Green - Fully Charged
* Amber - Partially Discharged
* Red - Almost Fully Discharged
* Flashing Red - Fully Discharged"
At the end of a cleaning mission, Roomba will tell you if it has successfully completed it's mission or not:

GREEN = MISSION COMPLETE

YELLOW = MISSION ABANDONED (Check robot's brushes, etc.)

YELLOW RED POWER BUTTON = BATTERY DEPLETED (Scheduler Models)

RED YELLOW POWER BUTTON = BATTERY DEPLETED (Discovery Models)
number of beeps after ?uh-oh? :

No beeps: A wheel is stuck or is not touching the ground. Pick up the robot, place it down securely on the floor and touch the clean button to restart the cycle.

1 beep: The main brushes cannot turn. Turn over Roomba and remove the brush guard by pushing the two yellow tabs. Remove the brushes, clear any obstructions, and replace them again.

2 beeps: The side brush cannot turn. Turn over Roomba. Look to see if something is wrapped around the side brush. Remove the side brush with a screw driver and check for string or hair that may be wrapped around it.

3 beeps: The vacuum cannot run Remove and empty Roomba?s bin.

4 beeps: A wheel motor cannot run Your Roomba may be stuck or something may be wrapped around a wheel. Look for something wrapped around the wheels. Push them in and out and make sure they turn easily.

5 beeps: The cliff sensors have failed or are blocked. Turn over Roomba and clear any debris that might be caught underneath the front bumper in the cliff sensors. You can also use compressed air to clean them out.

6 beeps: Wheel obstruction or robot attempting to drive over an obstacle. Turn over Roomba and remove any obstructions that prevent the wheels from seating all the way up into Roomba?s body. Also, remove any obstacles that Roomba could drive over.

7 or 8 beeps: Not applicable Roomba?s beep codes do not include 7 or 8 beeps. If you are getting an error with 7 or 8 beeps, try counting again or contact iRobot Customer Care.

9 beeps: Sensor error Please contact iRobot Customer Care.

10 beeps: Roomba is stuck Pick up Roomba and start it again somewhere else. Use a virtual wall or other barrier to keep Roomba away from the
place it got stuck.

Your Roomba may be experiencing an issue where the battery is deeply discharged and may need to charge longer than the standard 3 hours. (or 7 hours if you have a standard charger)

Even with the charging light showing green (this indicates a fully charged battery) the robot is still charging. If your Roomba exhibits behavior where it charges for a short time then runs for a short time you will need to do the following.

1. Plug the charger into Roomba (if you have a home base be sure to plug directly into Roomba instead of using the home base, this will ensure the robot's charging cycle is not interrupted.)

2. After the Roomba's charging indicator goes to solid green please keep the Roomba on the charger for an additional 72 hours. (3 days)

3. After the 72 hours (3 days) has passed, turn your Roomba on and begin a normal cleaning cycle. If this works successfully it may take several uses for the battery to get back up to the performance it once had.

If this does not correct the problem, please call customer support at 877-855-8593

see the diodes, resistor, capacitor inside for test.
since the battery is new, the power charger is faulty, power regulator IC is bad.
God bless you

Hi.

If the red light is solid, that means that the Roomba is near to full discharge. If the light is flashing red, then the Roomba is completely out of charge.

If the Roomba is fully charged, then there may be a fault.

Here full list of light codes:

Pulsing Amber - Charging
Green - Fully Charged
Amber - Partially Discharged
Red - Almost Fully Discharged
Flashing Red - Fully Discharged"

Here manual

See also
Roomba DISCOVERY MODELS' DIAGNOSTIC TESTS

Did you ever get an answer to your question on no power to your roomba? I purchased one for my parents off of craigslistthat was brand new; and has the same problem... charged for 16 hours - lite turned green - and no power! [email protected] Thanks

It could be the power button itself. If you have a Roomba remote, try using that to power on the robot.

Call iRobot. Your charger is broken.