Post a link to your power supply... If you are using Hitec 805bb servos DO NOT USE VOLTAGE ABOVE 6V you will burn your servos... I use a Meanwell 6V 50A power supply will no issues... What type are you using? Maybe you have destroyed your servos using 12V?

I have a Meanwell 5v 90a I was using at first with no success, I then unboxed a power supply 6v 50a from China which Gael recommended from the Inmoov website, I believe the name is Wenzhou or Sense I cannot find a name on the power supply or the link of it?

So the 6V/5V power supplies would not work to move even 1 servo?... Do they at least run the ezb4 and camera? Do you have a picture of these power supplies? Maybe the supplies are not outputting what they are supposed to... Stick with 6V max on Hitec 805bb (if that's what you are using) or you will damage them... Do you have the power supplies wired correctly to 120V AC (hot, neutral and ground wires)?

Yes, they power both ezb4's with no problem.

here is the link to the 6v power supply:

http://www.ebay.ca/itm/New-6V-Power-Supply-300W-6V-50A-Switching-Power-Supply-WITH-CE-/182703380182?hash=item2a89f856d6:g:dJ4AAOxyXHpSTJZ-

and here is the link to my meanwell power supply:

https://ca.mouser.com/search/ProductDetail.aspx?r=709-HRP450-5

Thank you for all your help.

Rob

Have you disabled the lipo power saver if only running 6v? No I/o will work if the power saved is on under the specified default voltage.

The ezb will repeat over and over forever "my battery is low". In which case, no I/o will work until disabled.

So just to be clear; you tested the servo's with my ezrobot 7.4 bower battery the servo works fine? However when you use one of the power supplies to test the same servo you get nothing?

Are testing through ARC or just hooking the servos up to power? There is a setting in ARC that won't let your servo to move if your under voltage. You need to disable this setting before ARC will move your servo.

Have you re-tested the servo on the battery after you tried the power supplies? If not you could have damaged the servo with to high voltage or using to low voltage and the servo won't move. I'm concerned you may have damaged your servo when you first supplied 12v to it.

I don't see anywhere in your posts what servo you're using. What are the specs and model of the servo are your using? If it requires more than 7 volts it may not move.

As RR mentioned, make sure all your wiring is correct, your supplying power within the proper voltage range per the servo's specs, and all your settings in ARC are correct when testing. If you are supplying voltage to the servo without using ARC to move it, you may not see it move. The only way it may move is if it's not centered when voltage is applied. Then it may move to center when powered up. If already centered then it will not move. However It's possible that it may hold position at center when leverage is applied after power up without a signal from ARC but I'm not sure. RR may be able to say. He's got a great understanding of servos and how they behave.

Your power supplies are more than capable of supply the amps needed to operate this one servo. You can't offer a motor to much current. It will draw what it needs. However you can starve a motor and it will draw more amps then can be supplied. This can damage the power supply or motor or melt wiring and connectors. eek Proper voltage is important. DC motors are tolerant of over (by a little) and under voltage. However when you add a control board to them and turn it into a servo then you must keep the voltage within specs. The little components controlling the position and speed of the servo need to operate within a certain voltage range or they can be damaged. Sometimes in a spectacular way. eek Then sometimes you don't even know. tired

After you are sure you have your supplied power within the proper range and all the connections and control methods are correct you may have to test with a new known working servo. Good luck.

I think @DJ may have the right answer... Servos won't run if the LIPO voltage monitor override is not active and the voltage is below a pre set value (7V is default). In other words If ARC thinks you are using lipos and the override is not active, servo movement will be disabled if battery voltage is 7v or less..

Thank you everyone for helping,

That is correct Dave, I have tested the servos after the incident with the 12v power supply using the with my ezrobot 7.4 bower battery the servo works fine.

I have disabled the battery monitor override in the settings. When I first connected the power supply it kept repeating low battery and I read a response someone had the same issue to disable it. Is this the correct way to disable the lipo power saver?

When I first used the 12v I had to replace two hs-805bb servos in my shoulder and bicep, unfortunately I fried them. My right hand forearm, bicep and shoulder were not completed yet. I'm using new ezb servos for the fingers for my right hand and hs-805bb for the rest all tested using the my ezrobot 7.4 power battery. Still no response from my servos on my right side using both power supply's.

Thanks again everyone for your help,

Rob