Asked — Edited
Resolved Resolved by Geoff!

No Power

My EZ Robot isn't powering up correctly. I just took the unit out of the box for the first time, completed the barrel wiring and connected it to the battery case. The unit did nothing until I picked it up and touched the heat sinks with two fingers when it flashed briefly (both blue and red) and then went dark. The batteries are fresh and I've checked the connections on the sinks and they seem fine. I've searched the boards but can't find a diagnosis.

Can anyone help?




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double check the wiring to the barrel adapter. also, do you have any servos connected?


No servos at all and I've checked the barrel (even re-wired a couple of times). I've now discovered if I hold the unit by the heat sinks the blue and red lights will activate but the moment I take the pressure off it goes dark.


Your EZ-B is suffering from cold solder joints on the two heat sinks and FETs. Use a dab of solder flux on the connections and apply heat from the tip of a soldering iron to re-flow the solder on each connection.


Hey Mulberry,

Robot-Doc might be onto something :)

We need the solder to reach a certain temp so that it can properly bond the two surfaces together. Usually, not always, you can see a cold solder joint because it tends to look "duller" or pale in comparison to a regular solder joint which tends to be shiny.

Let us know what you find!


The repairs suggested by Robot-Doc did not work. I'm at a loss as to what to do.


I'm having the same problem. I just opened my box today, also. No power.


Hmmm. I was told I could return if for repairs but have to cover the cost if they can't replicate the problem. I honestly can't chance doing any more work on it myself because of the investment so far. I was tempted to replace the fuse but couldn't pull the current one out. It seemed wedged pretty tight.


Scratch that....I don't have that problem. My kids had swapped out batteries from a new battery package. Instead of throwing the old batteries away, they just put their dead batteries in the package.



@Mulberry, you can pull up on the plastic portion of the fuse with a pair of needle nose pliers to remove it. Or if you have a multi-meter you could check the fuse for continuity by turning the EZ-B over and measure between the 4 solder tabs. Any two tabs on the left should have continuity with any of the other two tabs on the right.

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Also since you said that putting pressure (squeezing) the two heat sinks together would turn on the LEDs then look around the soldered contacts on the dc jack that is mounted to the board. It's possible that there could be a poor solder joint there as well. And while you're looking around make sure the screws that hold the two FETs against heat sinks are tight.

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Thanks Robot-Doc. I checked the fuse and it looks fine but now the unit doesn't flash when I hold it by the heat sinks. This must be a connection problem somewhere in that area. I think returning the unit for repair is my wisest option. I'm afraid if I mess with it anymore I may exacerbate the problem or worse damage the board beyond repair. As it stands if I don't get this working I may damage my marriage beyond repair.....



Thanks to everyone who chimed in on a solution. All were tried but I'm still unable to get stable power to the unit. EZ Robot will take a look at the unit and see what they can do. I'll keep my fingers crossed.