How to Troubleshoot a Dolphin Pool Cleaner


  3.64 out of 5 stars on 22 ratings
(Click on a star to add your rating)

What do you do when your Maytronics Dolphin Pool Cleaners stops running or there are no lights on the Power Supply? This guide shows you how to troubleshoot the electrical circuits of the Maytronics Dolphin Pool Cleaners so you can isolate your problem and replace the failed parts or parts. Our primary tool for testing these electrical circuits is a multimeter/voltmeter so we will first cover some of the basics of how to use a multimeter.

Click Here to View Replacement Dolphin Pool Cleaner Parts 



Step by Step


Step 1

REVIEW MULTIMETER BASICS - This is a picture of a typical multimeter. Most multimeters have more functions than we will use, For this series of tests, we will only be using the AC or DC voltage and continuity test functions.

Step 2

DIAL METER FOR AC TEST - The AC side of the meter has two test ranges. If you are testing for voltages between 0 and 200V, you would set your meter to 200. If you are testing for voltages above 200V and up to 600V, you would set your meter to 600V. Since we will be testing for 120V from the wall socket, we will be setting the meter to 200.

Step 3

DIAL METER FOR DC TEST - The DC side of the meter has four test ranges. the upper limits of which are labeled 2, 20, 200, and 600. Since we will be testing for DC voltage of 29V after the Power Supply Transformer, we will be setting the meter at 200.

Step 4

DIAL METER FOR CONTINUITY TEST - A continuity test measures for a break in an electrical line, like the Dolphin Cleaner cable. When running this test, the POWER MUST BE OFF, and the meter should be set at the continuity setting as shown.

Step 5

OVERVIEW OF TESTS - This picture lists the 6 tests we will conduct to isolate your Dolphin electrical problems. Each of these tests may be broken down into a series of subtests such as Test 3a, Test 3b, etc, depending on the success or failure at each stage of the test.

Click Here to View Replacement Dolphin Pool Cleaner Parts

Step 6

TEST 1A - CHECK WALL OUTLET -The power at the outlet should be around 120V so set the meter for 200 on the AC side of the multimeter. Then place the two probes from the multimeter into the wall outlet. If you see a reading of between 120V and 130V, your wall outlet is good and you have successfully passed Step 1. Jump to Test 2A - Check Power Supply.

Step 7

TEST 1B - If you see 0V on your multimeter, check the following: Circuit Breaker may have tripped; the GFCI at your outlet has to be reset; or your outlet is bad and needs to be replaced.

Step 8

TEST 2A- CHECK POWER CORD - Pull the power plug out of the Power Supply to test the power cord between the wall outlet and the power supply.

Step 9

TEST 2B- Insert the two multimeter probes into the female end of the power cord  The meter should be set to 200V AC as used in Step 1. If the reading is between 120V and 130 V, the power cord is good and you can proceed to Test 3A.

Step 10

TEST 2C - If the reading on the meter is OV, Check for a break in the electrical wiring of the cord. Set the meter for a continuity check. PULL THE POWER CORD OUT OF THE WALL OUTLET. Place one probe in one of the holes in the female end of the power cord. Place the other probe on one of the leads on the other end of the cord that plugs into the wall outlet. If it reads 0V, move the probe to the other lead of the wall plug. There are two wires in the cord for hot and neutral. You want to make sure you are testing the ends of the same wire for continuity. Move the probes to the ends of the other wire and test it for continuity, If you don't have continuity on both wires, the cord is bad and needs to be replaced.

Step 11

TEST 3A - CHECK AMPHENOL PLUG - Reconnect the power cord to the Power Supply. Plug the power cord back into the wall and turn the Power Supply ON.

Step 12

TEST 3B - Set your multimeter to 200 on the DC side of the meter. Insert the two meter probes into the socket of the Amphenol Plug. The meter should read close to 29V DC. If you see 29V DC, the Amphenolotor Plug is good and you can go to Test 5A to check the Dolphin Motor.

Step 13

TEST 3C -  If you got 0V in the previous step, you will need to take a closer look at the Amphenol Plug.TURN THE POWER OFF. Then unscrew the Amphenol Plug with a Phillips head screwdriver and pull it out of the Power Supply.

Step 14

TEST 3D - Remove the Amphenol Plug from the wires with a small Allen wrench. Note how the wires are attached so you can replace them correctly when the plug is reattached.

Step 15

TEST 3E - To retest the voltage coming out of the Power Supply first TURN ON THE POWER. Then place the meter probes on the two raw wires. Be careful not to touch the probes across the wires or you will short them out. If you get 29V DC on the raw wire and you saw 0V DC when you tested the Amphenol Plug in Test 3B, you will need to run a continuity test on the plug itself. If you get 0V DC on the raw wire, you will have to test the fuse inside the Power Supply for continuity. Go to Test 4.

Step 16

TEST 3F- To test the Amphenol Plug for continuity, first make sure the meter is in continuity mode. Then place a probe on either side of the plug as shown. Make sure to test both of the two circuits through the plug. If continuity fails, you will have to replace the Amphenol Plug.

Step 17

TEST 4- CHECK POWER SUPPLY FUSE - If you have an older style Power Supply, it will have a fuse inside that can be checked for continuity to see if it failed. The older style Power Supplies have screws in the bottom plate that can be removed for access to the fuse. If the continuity check on the fuse is negative, replace the fuse. If the fuse tests positive, the Power supply has an internal problem and you will have to replace the Power Supply. If your Power Supply is newer (without screws), it does not have a fuse and you will have to replace the Power Supply.

Step 18

TEST 5A - TEST DOLPHIN MOTOR - To test for a bad motor you will have to disconnect the Cable from the top of the motor. To get to the end of the Cable, first TURN OFF POWER. Using a Phillips head screwdriver, unscrew the middle screw and lift off the Impeller cover.

Step 19

TEST 5A - Remove the Cleaner Cover by unscrewing the screws at each the 4 corners and lifting off the Cover.

Step 20

TEST 5B - Place the ends of a pair of needle-nose pliers into the holes on top of the Cable Retainer Plug. Twist the plug counter-clockwise until it comes out and then slide it down the Cable.

Step 21

TEST 5C - Pull the Cable out of the top of the motor. It may take a little effort.

Click Here to View Replacement Dolphin Pool Cleaner Parts 

Step 22

TEST 5D -  Set the meter to 200 DC and check that the Dolphin Cable is attached to the Power Supply. TURN ON THE POWER SUPPLY. Then place the meter probes into the plug on the motor end of the Cable. If the meter shows 29V, you are getting power to the motor. If the Pool Cleaner does not respond, your motor is bad. At this point, if the Cleaner is not still under warranty, it is usually cheaper to buy a new cleaner than sending the cleaner out for a motor replacement. If the meter shows 0V DC go to Test 6A. There is something wrong with the Cable.

Step 23

TEST 6A - CHECK THE DOLPHIN CABLE - If you have 29V DC coming out of the Power Supply into the Cable (See Step 3B) and 0V DC at the motor end of the Cable,  you will want to run a continuity check on each wire in the Cable to verify that the Cable is broken and needs to be replaced.Remember to unplug the Cable at the Power Supply end. If the continuity checks are successful, check that you are getting a good connection at the end of the plug on the Power Cable and that all of the pins are in the Power Supply plug.

Step 24

REASSEMBLY THE CLEANER - Plug the Cable back into the motor and secure it with the white Cable Retainer Plug. Don't over tighten. Reattach the Dolphin Cover and Impeller Cover. Reattach the Cable to the Power supply.

Step 25

PRECAUTION 1 - During the operation of your cleaner, Make sure that your pool is free of toys or small objects that can get lodged in your cleaner and burn up the motor.

Step 26

PRECAUTION 2 - When your cleaner is not in use, pull it out of the pool and keep it unplugged to avoid lightning and power surges.

Step 27

DOLPHIN CLEANER IS READY TO GO - For further information or clarification, please use the live chat feature or submit a support ticket

Click Here to View Replacement Dolphin Pool Cleaner Parts


(1 to 40 of 59)

 Posted: 6/18/2022 

I have a Dolphin 115 power supply that will not power up I have 120 volt power verified to the DC board but no DC power. The AC glass fuse on the board has power on both sides. I have no DC

InyoPools Product Specialist  Posted: 6/30/2022 

What is the part number of your power supply? Almost all of Dolphin's power supplies sold for units in the US are meant for 115V.

 Posted: 5/29/2022 

Hello , My DX3 will not move nor will the impeller. The power supply comes on but the 3 leds for (1,2, and 3) do not blink and the power shuts off after a few seconds. If I unplug the cable and power on the power supply , the 3 lights blink and the power stays on like usual. Any ideas? I tested the cable for continuity and its good. I took apart the unit and found the drive gear and a guide wheel were busted up with bearings falling out. I took everything off the motor that would be a load and plugged it into the power supply, but get the same result. No humming or signs of life from the motors. Is there a way to test each motor individually and also the control board? Thank You for your time.

InyoPools Product Specialist  Posted: 6/2/2022 

The motor is receiving power but is not turning; if the shafts are frozen, the motor is dead and should be replaced. Depending on the age of the cleaner, it may be best to get a whole new unit because motors are expensive. There won't be much sense in spending a lot on a cleaner motor if the chassis does not last a couple of more seasons. 

 Posted: 4/22/2022 

The Dauphine cleaner works great .But only stays in one area of the pool around a 20 foot area.Doe’s not go to ends of pool.Vacuum works great just don’t get around all or pool.

InyoPools Product Specialist  Posted: 4/25/2022 

Have you done any of the troubleshooting?

 Posted: 4/5/2022 

When I test my nautilus cc plus out of water, is is the track supposed to spin only one way, or spin one way, then reverse the other way? Trying to determine if my motor is faulty, or if spinning only one way out of water is normal

InyoPools Product Specialist  Posted: 4/14/2022 

I don't know if it is supposed to spin freely, turning both ways. But we list a few different ways to troubleshoot the motor in the guide correctly. I'd go with those, as they are a more accurate way of testing the equipment. Whether or not the track spins could have more to do with guide wheels and brushes than the motor itself.

 Posted: 3/18/2022 

I forgot how to have my dolphin map the pool. It’s a 09/2005 model yellow

InyoPools Product Specialist  Posted: 3/21/2022 

The cleaner doesn't remember a map of the pool. You can drop it in, and it will go through its cleaning cycle.

 Posted: 3/12/2022 

I have a 4 year old dolphin premier that now often does not start moving, o r stops moving after few seconds or minutes, while tge impeller keeos working. I have checked/disassembled the moving parts outside the motor unit to make sure everything is clean and moving freely. On the 3 power supply pins, i get differential voltages of 28.8, 26.2, and 2.6v when the robot is not connected. Does the 2.6v voltage difference between two powered pins mean the power supply is ok, or that it needs replacement? Also, does one motor /impeller keeping working while the other turning off soon indicate a motor problem or maybe a yet to be found mechanical problem? Trying to determine if i need a new motor unit, power supply. Or cable (all 300 usd options). Please help!

InyoPools Product Specialist  Posted: 3/14/2022 

There are several tests we show to narrow down the possibilities. You have tested the pins on the power supply, but what about steps 17 to 23? If you are testing the circuit for voltage, you need to go the length of the circuit to see where the voltage stops. 

 Posted: 9/7/2021 

I checked the power going into the motor and it reads 27v There is 29v coming out of the power supply. My DX4 stopped working about a week ago. When powered on only the three blue lights,,, not the amber, The three blue lights flash for about a while then go out. A few days later after repeated trying, it ran.. but only for a day or so. Back to same problem. Power supply is putting out 29v, the end of the cable at the motor reads 27... but no go. Any thoughts?

InyoPools Product Specialist  Posted: 9/8/2021 

An educated guess would lead me to say it is a bad motor. When the cleaner does run intermittently, is it herky-jerky or does it run as usual?

 Posted: 8/20/2021 

I think Laura and I are having the same issue except now my power supply will not turn on at all now. I will work through the steps you have listed here and hopefully it is a cable issue. If not, are there steps to open the power supply?? It appears to be sealed pretty well. Thank you for making this post. It has provided me and others a lot of good information.

InyoPools Product Specialist  Posted: 8/23/2021 

What is the part number for your specific power supply?

 Posted: 8/16/2021 

I have the nautilus preimer. The top impeller and drive tracks quit working. The power supply is putting out 21.2 VDc (measured right at power supply). Okay Sounds like it is suppose to be 29 VDC.

InyoPools Product Specialist  Posted: 8/17/2021 

So, it sounds like the voltage is out of the desired range. Have you tried testing the cable as mentioned in step 6A (Step 23)?

 Posted: 8/9/2021 

Could you tell me why our power supply unit won’t stay on. It comes on for a bit then the just turns off the reset button and test button won’t work on the black power cable clicks off straight away.

InyoPools Product Specialist  Posted: 8/11/2021 

It could be a bad transformer or board in the power supply. But that is a guess. You would need to do some of the troubleshooting mentioned in the guide if you want any certainty.

 Posted: 5/13/2021 

I have a Maytronics 99996333-DX3 Dolphin Robotic Pool Cleaner. The impeller (in perfect condition-new) will not start, however, the wheels are working fine. The power supply is 2 years old. Could this be a power supply issue or is something else likely? Thanks!

InyoPools Product Specialist  Posted: 5/14/2021 

If it was a power supply issue, the motor wouldn't run at all. The cleaner m0tor has two functions, to run the drive shaft that turns the tracks and the shaft the spins the impeller. Sometimes these jobs are done by one motor or two separate motors just mounted in the same box. It sounds like your impeller motor has failed. Unfortunately, there isn't much left besides replace the motor or take it to a motor shop to see if it can be repaired.The replacement motor for the DX3 is the Motor Unit D.basic 3 Hour Ac New (99953003-assy)

 Posted: 4/18/2021 

I have a maytronics DX3 pool cleaner and the power supply have 123 volts going in to the power supply and there are 63 volts coming out of the power supply. I check the power to the robot and it has 62 volts and will not come on and move. Any help would be greatly appreciated.

InyoPools Product Specialist  Posted: 4/21/2021 

Something is wrong with the DX3 power supply or your voltmeter because the output should not be higher than 29 volts. You can check to make sure your meter is set correctly, or try a different one. If you verify the reading, you would need to replace the power supply with the newly updated version 99956002RD-ASSY

 Posted: 4/13/2021 

I am trying to troubleshoot my Dolphin Premier cleaner. Power supply powers up but I am not getting any activity at the cleaner itself. I have followed the troubleshooting techniques in your video, but would like to get something clarified. You show only 2 wires coming into the amphenol plug. I have three wires - a black, white and red. Can you tell me what the voltage reading should be across the red wire?

InyoPools Product Specialist  Posted: 4/16/2021 

The voltage should be around 29 volts, like the 2-wire version. The red wire is the ground.

 Posted: 12/8/2020 

Model 9995678 power supply, Power light comes on steady, no mode selection lights come on any longer. Ran the tests recommended and no DC voltage comes out the amphenol plug or wires into back of plug. Any boards or internal fuse etc. replacable?

InyoPools Product Specialist  Posted: 12/9/2020 

The only replacement parts I could find for the 9995678-US-ASSY were the Amphenol socketAmphenol socket cover, and the black cable.

 Posted: 9/8/2020 

I ran diagnostic tests on my Maytronics power supply, P.No. 9995670, PD 5012, SN HG5012A10956 The power outlet, and supply cable test good, 120 v. When first powered on, the blue lights come on, and 29 v register on the DC out. After 2.5 minutes, the power light goes out, and the DC voltage drops to .01, then fades to 00. It will not power back on, unless the power cord is disconnected from the supply for 15 sec or so. Once powered back on, the same cycling happens, lights stay on for 2.5 mins or so, power 29v on DC out, then fades to 00 again. Does this indicate that a new power supply is needed? The DC out plug has continuity.

InyoPools Product Specialist  Posted: 9/10/2020 

It sounds like you have a power supply failure. You can try replacing a couple of the boards in the box, but the endgame is almost always getting a new power supply within a month or two. the whole power supply is the 9995670-US-ASSY. The power supply PCB for your power supply, p/n# 9995453LF

 Posted: 7/26/2020 

my power light switch will light up but the 1 2 3 cycle lights will not come on.

InyoPools Product Specialist  Posted: 9/3/2020 

What is the part number of your power supply? If you do not have that, what is the model of Dolphin cleaner you own?

 Posted: 7/18/2020 

13 year old Dolphin M4 Supreme suddenly stopped working Power supply lights up and I can select any of the three weekly programs, but the motor never starts either in the water or on dry land. Troubleshooting: Amphenol plug (3 pins) DC voltage: 28, 26 and 1.9 for the different pin combinations End of cable going to motor (3 pins): 28, 26 and 1.9 for the different pin combinations Resistance of cable: 0.9, 0.6 and .OL (open) for the 3 different wires Not quite sure how to interpret the voltage on the amphenol plug. Looks like one of the wires in the cable is broken. What do you think? Just replace the cable or is the power supply bad as well? Thanks.

InyoPools Product Specialist  Posted: 9/10/2020 

It appears you found the issue, the wire is broken and the resistance reading is "open." The "open" reading means there is no circuit continuity; I presume you need a new cable. The Dolphin Supreme M4 uses the 9995873-DIY.

Anonymous  Posted: 6/29/2020 

I am not getting any voltage out of the unit. I have a more recent unit, so I seem to see a fuse solded to the board. Can I replace that fuse or do I have to replace the whole board ? Thanks

InyoPools Product Specialist  Posted: 9/23/2020 

What is the part number of the power supply?

 Posted: 5/26/2020 

Hi. I need to replace my power pack 995675. Is power pack 995670 compatible?? Thanks!!

InyoPools Product Specialist  Posted: 10/23/2020 

You are missing a '9' at the beginning of both of those part numbers. The correct replacement for your cable is the 9995675-US-ASSY

 Posted: 5/23/2020 

Blue light on power source comes on. I have checked all of the cables everything seems fine. Cleaning unit itself is not coming on. Figuring possibly a blown motor?

InyoPools Product Specialist  Posted: 10/23/2020 

Yes, if the motor is receiving power but still is not moving, you have a blown motor. What is the model name or the serial number of your Dolphin cleaner?