Asked — Edited
Resolved Resolved by DJ Sures!

Help On Recovering From A Stupid Moment On The Ezb

I got my head all back together and the neck, etc. I have a battery going through a 640 ohm resistor to a female extention plug. I plug this in to test the LEDs. Each one worked very good but one did not. I checked reverse polarity on the circuit and the LED worked. I did not want to take the head all apart again (hassel). So , I simply turned the plug around not realizing if i were hurting something or not. But, it did not seem that it would damage the EZB because I was simply swapping ground and signal. I can't see very well, I may have plugged a plug in shifting one pin over. that would connect ground to hot or signal to hot.

Anyway, boiling it down, All of my digital pins do not work anymore.

Any ideas? I am thinking voltage regulator blown, I hope it is not the cpu. I am going to run the test that D.J. has and try to figure it out. The lights blink red and blue and it connects up. So , the bluetooth is working.

Wish me luck.


Upgrade to ARC Pro

Experience the transformation – subscribe to Synthiam ARC Pro and watch your robot evolve into a marvel of innovation and intelligence.


If the lights are blinking, it most likely is the voltage regulator. Let me know if you have trouble replacing it and we'll see what we can do to help you out:)


I got my five volts on there. Also, ALL of the digital pins do not work. I have not checked the analog.

@ DJ, what are the voltage regulator values, I know one is 5 volts. Is the other 3.3 volts? I am getting 3.3 where it says 3.3 on the print. And, I am getting 5v where it says 5v. Also, I am showing 7.2v coming in.


One regulator has 7.2v coming in and 5 volts going out.

The other one has 5v coming in and 2.19 going out. That is the one I think is bad. I need to know the value so I can change it. I have a lot of regulators in stock. This is probably the 3.3 regulator. But, I need to know.

Thank you.



Please, What is the voltage value of the one closest to the plug?


I'm on a plane. Landed between layover. You need to learn patience movie maker:)

5 volts is the ezb except for the pin labelled 3 volts. You know these answers because the board is labelled:P



I still don't understand. You are saying you have a 5 volt regulator ie; 7805. And you have a 3.3 volt regulator?

VR1 is the one that has the problem. But, is it a 3V regulator or a 3.3 volt regulator? I just want to be sure before I purchase it. I have plenty of 5 and 12v regulators.

I see two. I know which one is 5 volts, but I have to be sure the other is 3V. My eyes are bad and I don't see it labeled ,but I will look again.

Thanks, and sorry to bother you on the plane.



Creating another thread on this topic will result in banning. Your other thread has been removed. This is your last warning.

The voltage out of both of the heat sync regulators is 5 volts. The voltage out of the small regulator is 3 volts. These voltages are labeled.


I would hope not to be banned.That would break my heart. I LIVE for this forum and the EZB. It is what I do. I am elderly and handicapped. I have trouble communicating because the part of my brain that understands doesn't. I am not trying to get smart. I am just sick. People have to explain things to me very carefully. I just wanted to know the value of the regulator next to the plug. It was that simple. I see a +5v and +3.3v on the ezb about mid section. That is not on the regulator. I am curious about VR1. Simple 5v,12v,3v. the way you worded it was that BOTH of the regulators were 5v regulators and another section had the 3.3v regulator. That is fine, I just need to know.

Anyway, because of my disease I will ask you to give me kind consideration and respect. you are in your prime like I used to be. You may one day have to deal with this. I pray you don't. I have always shown you respect and admiration like my own son.

It was a new question. This is my final warning, but I don't remember ever having been warned before. I thought I had a clean record. I am really trying hard. I post more posts when I am actually using the product then when I am not. Have I posted too many times? Is there a protocol? Thank You, my friend. Hope that you have a nice flight. sorry if I have taken up too much of your time.



I would measure off of my good EZB to see what all this is. BUT, I have it hot melt-glued down to the bottom of the robot where I cannot get to it easily. I hadn't planned to pull it out so it is really solidly placed. I may damage it if I try to pull it out. That is why I asked for information from some of my friends here on the forum. God Bless;)


I already offered that we would help you replace the regulator. I can't have you flooding the forum with questions on the same topic please. It's the one rule that will get temporary banning. Just don't make another thread on this topic and it'll be fine:)

As for your regulator, if you do not get +5 volts on the I/O pins, then the VR is damaged. If you are afraid to swap it yourself, I offered to do it for you. Contact Us and we'll have you ship it to us for repair


@MovieMaker - The 5 volt regulation that is done on the EZ-B consists of two different devices. The part numbers are: LM1084 IT 5.0 / NOPB
and MIC29300 5.0WT

You can order them from


Thank you both.

D.J., I am happy that you are not banning me yet. I can change them myself.

@robot-Doc, Is this the same as the 7805 voltage regulator, I have a million of those. I don't know if the are Field-Effect transistors or not. I just know that they are on most pieces of computer equipment I have.

OK, so BOTH regulators are the same? 5volt. That answers my question if you will confirm.




OK, I sort of understand. I am getting my +5v on all of the digital and analog ports. My bluetooth connects. But, I cannot control the digital ports. I think maybe my cpu is bad.

Please confirm.




Hello @MovieMaker,

This forum post should help you out. Both Regulators aren't the same on the EZ-Bv3. Something to be aware of is that the LM1084-5.0 while being a similar 5V linear voltage regulator (not a FET) it doesn't have the same pinout as the common 7805 or the other regulator the on the board: MIC29300.

So you are no longer getting 2V on the Digital 5V line, it's back to 5V?


Thanks @skater_i10 for the correction to my earlier post. That post has been edited to reflect that there are two different part numbers for the two 5 volt regulators on the EZ-B V3 board that are mounted to the two heat sinks.

  1. LM1084 IT 5.0 ( VR1 )
  2. MIC29300 5.0 WT ( VR2 )

Both of those devices can be ordered from


OK,Now which is VR1 and which is VR2?

You STILL think it is the regulators even though I have +5v on all the power pins going to the digital and analog ports? and the place where it says 3.3v I have 3.3 volts. And the place it is supposed to be 7.2v , I have that. On the i/o pins, I will have to check for the signal pins and see what voltage are on them.

Thank You soo much.


Ok, I am all set. I know where to get the regulators. And I know which ones. That part is done.

But, which regulator goes on VR1 and which regulator goes on VR2.

And, If I am getting my 3.3v and 5v and 7.2 in the right places, maybe it is NOT the regulators.

What do you think?

I hate to ask so many questions, but I don DON'T want to burn up the EZB.

Here are my latest readings:

On VR-1 =7.2v going in =5v going out On VR-2=7.2v going in =5v going out On digital lines= 5v on power = 0v on ground = 2.1v on signal line. On PC Board the 3.3v = 3.3 volts

It all sounds correct to me. But, (NONE of the I/o works.)
But, the wireless connects as promised.

Thanks,D.J., Skater, and Robodoc. You have all helped me countless number of times.

I would like to hear what RICH has to say. :-)



This is just a repeat of the 5 volt regulators that now includes the Printed Circuit Assembly Board designations.

  1. LM1084 IT 5.0 ( VR1 )
  2. MIC29300 5.0 WT ( VR2 )

You should check with EZ-B support for what might be failing on your V3 EZ-B.

United Kingdom

I've stayed out of this one as it's stuff I don't know too much about (as in I've never really looked at the circuitry of the EZ-B or run diagnostics).

If you are struggling with it I'm sure if you send it to the EZ-Robot's team they will take a look at it and sort it out.

The only thing in addition that I can think to do, and it probably wouldn't help at all but worth a try is to set up 20 test LEDs (one per port) and set up a simple script or add controls to turn the LEDs on and off.

SET(D0, On)
# Continue for the other 19 ports...


I did that sort of. I got one LED and hooked it to the 3 wire connector and tested one at a time. None of the ports toggled on and off.


thank you both! Now I know the answer to my question. Which if VR1 and VR2. Thank you, robo-doc.

I have sent an email to the support team.


United Kingdom

Silly question maybe but I assume you have double checked that the LED works and it is the EZ-B not the LED that's not working?


RICH, good point. But NO, I tried it on several devices also and several LEDs. Here is what is happening:

LEDs flash-I can hook to bluetooth. All voltages are what they should be. CPU has zero ability to turn digital and analog ports on and off. They just stay off.

I think it is the cpu.

I have contacted customer support.


Not ever seeing an EZB board in real life, myself.... VR1 and VR2 should be labeled... Grab a magnifying glass or get someone with good eyes to read what's stamped on them....


The writing on the chip is very very faint. But, someone has pointed out which chip is where for me, Bless them.


@rryerson, that's what I used to determine which component was mounted to VR1 and VR2.

United Kingdom

@Mel, you were not clear if you had tried the LEDs on a known good supply/determined that the LEDs are in fact OK.

Either way, EZ-Robots will sort it out for you


Yes, Mr. Rich, I tried TESTED GOOD Leds and also servos. NOTHING on all ports. Just 1.5v-2.1v.


Now don't ask me why, but some of my ports are working again. I will test them all and report back.


I tested every digital port and analog port. And, guess what? They ALL are working correctly. I must've re-seated the cpu. That is the ONLY explaination that I can come up with. I used a servo to test the digital and made it move. Then I used a servo on the ADC ports and when I moved the horn a bar graph showed the move.

Thank you, Jesus! I am sooo happy. Sorry to have wasted all of you precious people's time. I guess the answer was re-seating the chip.



I CAN'T BELIEVE IT! My problem is Back!

OK, I went through every port. It works with the servo. But, it won't turn a simple blue LED on and off. I test the little light on the battery connection and it works fine. But, not on the ezb. It is the same type of setup that I have used in several generations of robots. It is amazing. It is blowing my mind.


I was so happy. But , it was short lived. My digital ports do not work. I have only an LED hooked to them. It won't turn it on and off. All of the voltages are measuring fine. I just did a check and Most ports are not working. Only a couple of them. Please Help! This is getting old.

I have turned in a notice to the staff, but I haven't heard from them.

Thank you,



You have an email....


@mel go ahead and replace the regulator. Testing components that are going bad or are damaged can result in erratic malfunctions. Do the suggested repairs then go from there:)


Thanks, Josh. The factory has said that they would repair it and will give me an RMA. I am affraid that if I try to fix it, they will not work on it after that. But, there is the waiting thing. I hate to wait. I am the worlds most impatient man. I can help it. I am wired this way.


I just found out something else. The cheapest shipping with a tracking # =$25.17. I am not going to pay over $50 to have it repaired. I may try those regulators.


Hi Mel, Totally up to you, however we will not repair the board after someone else has altered it in any way. If you are confident in your abilities, that would be the cheaper way to go.


@mel that's why you should keep a spare board ! Lol I'm impatient to the max so I understood. I would suggest you let mark ( or appropriate representative) get the board repaired for you. This way there is no guessing and you know it's 100 percent repaired.


@jstarne1 Ha ha, no way I will be touching that board! The goal is to get it fixed, not turned into a permanent paper weight!


@ Mark , Sorry! Lol I haven't had much interaction with you since you came aboard EZ-Robot so I wasn't sure of you role. Epic soldering skills might not be on the resume:).

@mel I mean if you can send it in the the factory I would do that.


It costs too much. Unless you want to put a downpayment on your turtlebot.


@jstarne1 Im strictly on the business side... more then likely it would be Jeremie.


Ohhhhh noooooo, don't tell them my real secret identity will be revealed!:D


@mel have you already ordered/ purchased the voltage regulator?


I have ordered the new version4. I plan to get the regulators at radioshack today. I hope they have both of them.


OK, I ordered the Lm1084 IT 5.0/NoPB.

When I do a search for the %A LDO POS REG, it puls up the LM1084. Am I missing something? or are they the same chip. It seems like they have a different pinout. I need the part # to the VR2.




Nevermind. i got the numbers mixed up. I do that a lot now.


OK, we can close this thread because EVERY Port is working now. As it turns out, after replacing the two rectifiers and the diode that all I needed was to take the cpu out and put it back. I am SO Happy. I was getting EZB withdrawals.:D


Yeah, but did you not do that once already and it only worked briefly?


Yes, that is true. But I did not completely remove the cpu. When I did, I felt something like metal fall out of the socket area and fall to the floor. But, I couldn't find it. You have a good memory. Better than mine.:D


Well, cross your fingers and lets hope it works permanently for you this time...;)