No power at all? or does the ezb just not make any sound when you turn it on? If there is no power (no sound, no lights) then first thing to do is check the fuse..

The fuse by the way is inside JD's body next to the battery... You will need a small philips screwdriver in order to remove the back cover to access the battery and fuse... Here is the fuse and battery replacement tutorial... JD Fuse and battery replacement

Thank you for the feedback, after reading your post, I checked the fuse (using a multimeter) and it was intact and still conducting electricity.

Since you have a multi meter, what is the voltage of the battery? Is there any life at all when you turn on JD or is he completely dead?..

Also check the switch to make sure it is passing power when switched on

The switch is passing power when its turned on. The is completely charged.

Couple more tests. With you multimeter and the switch on, see if you are getting power at the power and ground pin of any digital port. Even if the EZ-B itself is "dead", it should have power there. If it does, but the EZ-B won't start, it is probably an EZ-B problem. If not, then it is probably a power supply problem, and I would go back through all of the tests Richard already suggested, checking for power at each connection and transfer point.

Another option, since you have multiple JD's, I would try moving the EZ-B from the non-working one to a working one (I know, it is a pain because of all the cables. Maybe if you put them very close together most of thee cables will reach) just to see if the problem follows the EZ-B or if it follows the JD body.

If it follows the EZ-B itself, it is probably a damaged EZ-B. If it follows the body, then again, recheck power at each connection point, and verify the battery is providing sufficient voltage. I don't know how long you have had your JD's, but LiPo batteries last about a year or two even under the best of conditions, and a classroom is usually a fairly abusive condition for batteries (device gets left turned on long past the battery warning, etc....).

Alan

Its not the fuse, I tried the EZB "brain" on other JDs and it doesnt work, however other JD's brains do work in the body of the JD that has the broken brain.

Since its an issue with the EZB "brain" what can I do to troubleshoot and prevent this from happening?

Any suggestions?

Thank you in advance for your help.

@mcriscitello Use the Contact Us link to arrange to send it back for repair or warranty (depending how old it is)...

Turned out to be the EZB. I was sent a replacement. Thank you all who helped !